feat: per-change-block hunk actions (#50), codex lanes without a pipeline, macOS LaunchAgent

- git (#50): stage-hunk/discard-hunk take an optional `block` — one run of
  consecutive +/- lines inside an @@ hunk. `onlyBlock` (server/lib/git-diff.js)
  cuts git's fresh hunk down to it, folding the other blocks into the side
  being checked; LaneDiffView hangs one review bar per block (unified + split)
  and its arrows walk blocks.
- git exclude: entries AgentHub writes for a lane go to the COMMON git dir with
  the lane's path prefix (server/lib/git-exclude.js, used by router-apply and
  lane-mcp) — a linked worktree's own info/exclude is never read by git, and a
  subdir lane has no .git. MCP sync no longer fails with ENOTDIR on a worktree
  lane or creates a stray .git in a non-repo lane.
- codex lanes carry no pipeline: codex-ingest mirrors only idle/running,
  codex-nudge is removed, agents install writes nothing for codex, the
  Workspace hides stage/pipeline/feature pickers/PipelineMap for them, and
  every server start clears leftover codex stage data and the old AGENTS.md
  stage block.
- Changes panel: a whole file opens for reading and enters the editor on a
  click on its text (caret at the clicked line), not automatically.
- macOS: LaunchAgent start-at-login (scripts/launchd-service.js, picked by
  scripts/service-manager.js).
- Adds the AgentHub introduction slides and their image-embedding script.

client/src/components/lanes/LaneCard.tsx

@@ -363,19 +363,22 @@ export function LaneToolsMenu({ lane }: { lane: Lane }) {
           role="menu"
           className="absolute right-0 z-10 mt-1 min-w-44 overflow-hidden rounded-md border border-border-light bg-surface-0 py-1 shadow-lg shadow-black/40"
         >
-          <button
-            type="button"
-            role="menuitem"
-            data-testid="lane-agents-install"
-            onClick={(e) => {
-              e.stopPropagation();
-              setToolsMenuOpen(false);
-              void handleAgentsInstall();
-            }}
-            className="block w-full px-3 py-1.5 text-left text-fg-secondary hover:bg-surface-2"
-          >
-            {t("actions.agentsInstall")}
-          </button>
+          {/* Claude-only: a codex lane has no agents to install. */}
+          {lane.tool !== "codex" && (
+            <button
+              type="button"
+              role="menuitem"
+              data-testid="lane-agents-install"
+              onClick={(e) => {
+                e.stopPropagation();
+                setToolsMenuOpen(false);
+                void handleAgentsInstall();
+              }}
+              className="block w-full px-3 py-1.5 text-left text-fg-secondary hover:bg-surface-2"
+            >
+              {t("actions.agentsInstall")}
+            </button>
+          )}
           {lane.tool !== "codex" && (
             <button
               type="button"

client/src/components/lanes/LaneChangesPanel.tsx

@@ -51,7 +51,7 @@ import {
   UnfoldVertical,
 } from "lucide-react";
 import { api } from "../../lib/api";
-import { LaneDiffView, LaneFileView, type DiffLayout } from "./LaneDiffView";
+import { LaneDiffView, LaneFileView, type DiffLayout, type LaneDiffChange } from "./LaneDiffView";
 import { LaneConflictView } from "./LaneConflictView";
 import { LaneGitHeader, useLaneGitFacts } from "./LaneGitHeader";
 import type {
@@ -59,7 +59,6 @@ import type {
   LaneChangeRange,
   LaneChanges,
   LaneCommit,
-  LaneDiffHunk,
   LaneTreeEntry,
 } from "../../lib/types";
 
@@ -454,10 +453,33 @@ export function LaneChangesPanel({
   // The whole-file editor's text while it is open; null = viewing.
   const [draft, setDraft] = useState<string | null>(null);
   const editWanted = useRef(false);
+  // Where the editor opens: the line clicked in the read view, and that view's
+  // scroll offset, so the text does not jump when the textarea replaces it.
+  const editAt = useRef<{ line: number; scrollTop: number } | null>(null);
+  const editorRef = useRef<HTMLTextAreaElement>(null);
+  const editing = draft !== null;
+  useEffect(() => {
+    const at = editAt.current;
+    const el = editorRef.current;
+    if (!editing || !at || !el) return;
+    editAt.current = null;
+    const offset = el.value
+      .split("\n")
+      .slice(0, at.line)
+      .reduce((n, l) => n + l.length + 1, 0);
+    el.setSelectionRange(offset, offset);
+    el.focus({ preventScroll: true });
+    el.scrollTop = at.scrollTop;
+  }, [editing]);
+  const startEdit = (line: number, scrollTop: number) => {
+    if (!text?.sha) return;
+    editAt.current = { line, scrollTop };
+    setDraft(text.lines.join("\n"));
+  };
   useEffect(() => {
     if (!editWanted.current || !text) return;
     editWanted.current = false;
-    if (text.sha) setDraft(text.lines.join("\n"));
+    if (text.sha) startEdit(0, 0);
     // Asked for from the diff, refused once the file arrived: say why here,
     // not with an Edit button that silently does nothing.
     else setError(t(noEditReason(text)));
@@ -786,16 +808,22 @@ export function LaneChangesPanel({
   };
   const resolve: Resolve = (path, side) => void mergeAct("resolve", { path, side });
 
-  // One hunk, matched by its `@@` line against a fresh diff at the context
-  // this diff was read with — so the server never applies a stale patch.
-  const actHunk = async (action: "stage-hunk" | "discard-hunk", path: string, hunk: string) => {
+  // One change block, named by its hunk's `@@` line and its index inside that
+  // hunk, matched against a fresh diff at the context this diff was read
+  // with — so the server never applies a stale patch.
+  const actHunk = async (
+    action: "stage-hunk" | "discard-hunk",
+    path: string,
+    change: LaneDiffChange
+  ) => {
     const lane = laneId;
     setBusy(true);
     setError(null);
     try {
       await api.lanes.gitAction(lane, action, {
         path,
-        hunk,
+        hunk: change.hunk.header,
+        block: change.block,
         context: data?.available ? data.context : undefined,
         ...(action === "discard-hunk" ? { confirm: true } : {}),
       });
@@ -810,13 +838,13 @@ export function LaneChangesPanel({
     }
   };
 
-  // Stage / Undo on each hunk of a file with unstaged changes. The diff is
+  // Stage / Undo on each change block of a file with unstaged changes. The diff is
   // HEAD → working tree, so a staged-only file gets none: undoing its tree
   // would leave the index holding the change.
   const hunkActions = (f: LaneChangeFile) =>
     range === "work" && f.unstaged && !f.untracked && !f.binary
-      ? (hunk: LaneDiffHunk) => {
-          const key = `${f.path}\n${hunk.header}`;
+      ? (change: LaneDiffChange) => {
+          const key = `${f.path}\n${change.hunk.header}\n${change.block}`;
           const armed = armedHunk === key;
           return (
             <>
@@ -826,7 +854,7 @@ export function LaneChangesPanel({
                 title={armed ? t("changes.undoHunkConfirm") : t("changes.undoHunk")}
                 disabled={busy}
                 onClick={() =>
-                  armed ? void actHunk("discard-hunk", f.path, hunk.header) : setArmedHunk(key)
+                  armed ? void actHunk("discard-hunk", f.path, change) : setArmedHunk(key)
                 }
                 className={`${HUNK_CHIP} ${
                   armed
@@ -841,7 +869,7 @@ export function LaneChangesPanel({
                 aria-label={t("changes.stageHunk")}
                 title={t("changes.stageHunk")}
                 disabled={busy}
-                onClick={() => void actHunk("stage-hunk", f.path, hunk.header)}
+                onClick={() => void actHunk("stage-hunk", f.path, change)}
                 className={`${HUNK_CHIP} border-status-success bg-status-success/25 text-status-success hover:bg-status-success/35`}
               >
                 {t("changes.stageHunkShort")}
@@ -887,12 +915,6 @@ export function LaneChangesPanel({
       return next;
     });
 
-  // Full width edits in place: an editable whole file IS the editor, and
-  // Cancel just puts the saved text back (this effect re-seeds the draft).
-  const editableText = full && mode === "file" && whole && range !== "commit" && text?.sha;
-  useEffect(() => {
-    if (editableText && draft === null && text) setDraft(text.lines.join("\n"));
-  }, [editableText, draft, text]);
   const dirty = draft !== null && draft !== text?.lines.join("\n");
 
   const files = data?.available ? data.files : [];
@@ -912,8 +934,8 @@ export function LaneChangesPanel({
     }
   }, [data, files, confirmDiscard]);
 
-  // A tree or quick-open pick opens the whole file. Always-on editing (full
-  // width) makes a stray click here the easy way to lose typed work.
+  // A tree or quick-open pick opens the whole file — and, with an edit open,
+  // would drop it, so a dirty draft asks first.
   const openWhole = (p: string) => {
     if (dirty && !window.confirm(t("changes.dropEdits"))) return;
     show(p);
@@ -1408,6 +1430,9 @@ export function LaneChangesPanel({
                     />
                   )}
                   {/* Only the working file is editable: a commit is history. */}
+                  {/* The whole file enters the editor by a click on its text;
+                      only the diff, which has no whole text to click, keeps
+                      an Edit button. */}
                   {range !== "commit" &&
                     (draft === null && whole && text && !text.sha ? (
                       <span
@@ -1416,16 +1441,21 @@ export function LaneChangesPanel({
                       >
                         {t(noEditReason(text))}
                       </span>
+                    ) : draft === null && whole ? (
+                      text && (
+                        <span className="shrink-0 self-center text-[10px] text-fg-muted">
+                          {t("changes.clickToEdit")}
+                        </span>
+                      )
                     ) : draft === null ? (
                       <button
                         type="button"
                         data-testid="lane-file-edit"
                         disabled={busy}
                         onClick={() => {
-                          // From the diff the file is not loaded yet: the
-                          // editor opens as soon as the whole-file read lands.
-                          if (whole && text?.sha) setDraft(text.lines.join("\n"));
-                          else editWanted.current = true;
+                          // The file is not loaded yet: the editor opens as
+                          // soon as the whole-file read lands.
+                          editWanted.current = true;
                           setWhole(true);
                         }}
                         className="flex shrink-0 items-center gap-1 self-center rounded border border-border-light px-1.5 py-0.5 text-[11px] text-fg-secondary hover:bg-surface-2 hover:text-fg-primary disabled:cursor-not-allowed disabled:opacity-40"
@@ -1446,7 +1476,7 @@ export function LaneChangesPanel({
                         </button>
                         <button
                           type="button"
-                          disabled={busy || (full && !dirty)}
+                          disabled={busy}
                           onClick={() => setDraft(null)}
                           className="shrink-0 self-center rounded border border-border-light px-1.5 py-0.5 text-[11px] text-fg-secondary hover:bg-surface-2 disabled:opacity-40"
                         >
@@ -1457,6 +1487,7 @@ export function LaneChangesPanel({
                 </div>
                 {whole && draft !== null ? (
                   <textarea
+                    ref={editorRef}
                     data-testid="lane-file-editor"
                     aria-label={t("changes.editorLabel", { path: openFile })}
                     value={draft}
@@ -1478,6 +1509,7 @@ export function LaneChangesPanel({
                       lines={text.lines}
                       truncated={text.truncated}
                       fill
+                      onEditAt={range !== "commit" && text.sha && !busy ? startEdit : undefined}
                     />
                   ) : (
                     <p className="text-[11px] text-fg-muted">{t("changes.loading")}</p>

client/src/components/lanes/LaneDiffView.tsx

@@ -273,10 +273,13 @@ function Gutter({ n }: { n: number | null }) {
 function Row({
   tint,
   style,
+  anchor,
   children,
 }: {
   tint: string;
   style?: CSSProperties;
+  /** This row starts change block `anchor` (file-wide): the bar's arrows land here. */
+  anchor?: number;
   children: React.ReactNode;
 }) {
   return (
@@ -284,6 +287,7 @@ function Row({
       className={`flex w-max min-w-full ${tint}`}
       style={style}
       data-diff-item={style ? "" : undefined}
+      data-change-index={anchor}
     >
       {children}
     </div>
@@ -305,40 +309,82 @@ function markerClass(type: LaneDiffLine["type"]) {
   return "text-fg-muted";
 }
 
-/** Per-hunk review controls (Undo / Keep), drawn in a bar under each hunk's
- *  last changed line. A context rather than a prop because lines render from
- *  four places; `hunks` is what the bar's "n of N" and its arrows walk. */
+/** One change block: a run of consecutive +/- lines inside a hunk. git merges
+ *  edits a few lines apart into one `@@` hunk, so the review bar acts on these
+ *  instead (#50) — `block` is the index the server's `stage-hunk` /
+ *  `discard-hunk` take beside the hunk's header. */
+export type LaneDiffChange = {
+  hunk: LaneDiffHunk;
+  block: number;
+  /** First/last index in `hunk.lines` (unified). */
+  firstLine: number;
+  lastLine: number;
+  /** First/last split-view row. */
+  firstRow: number;
+  lastRow: number;
+};
+
+const blocksOf = new WeakMap<LaneDiffHunk, LaneDiffChange[]>();
+
+/** A hunk's change blocks, cached per hunk object like `analyseHunk`. */
+export function changeBlocks(hunk: LaneDiffHunk): LaneDiffChange[] {
+  const hit = blocksOf.get(hunk);
+  if (hit) return hit;
+  const out: LaneDiffChange[] = [];
+  const owner = new Map<LaneDiffLine, LaneDiffChange>();
+  hunk.lines.forEach((line, i) => {
+    if (line.type === "ctx") return;
+    let c = i > 0 && hunk.lines[i - 1]!.type !== "ctx" ? out[out.length - 1] : undefined;
+    if (!c) {
+      c = { hunk, block: out.length, firstLine: i, lastLine: i, firstRow: -1, lastRow: -1 };
+      out.push(c);
+    }
+    c.lastLine = i;
+    owner.set(line, c);
+  });
+  analyseHunk(hunk).rows.forEach((r, i) => {
+    const c = (r.left && owner.get(r.left)) || (r.right && owner.get(r.right));
+    if (!c) return;
+    if (c.firstRow < 0) c.firstRow = i;
+    c.lastRow = i;
+  });
+  blocksOf.set(hunk, out);
+  return out;
+}
+
+/** The block whose last line (unified) / last row (split) is `i`, if any. */
+const barAtLine = (hunk: LaneDiffHunk, i: number) =>
+  changeBlocks(hunk).find((c) => c.lastLine === i);
+const barAtRow = (hunk: LaneDiffHunk, i: number) => changeBlocks(hunk).find((c) => c.lastRow === i);
+const startAtLine = (hunk: LaneDiffHunk, i: number) =>
+  changeBlocks(hunk).find((c) => c.firstLine === i);
+const startAtRow = (hunk: LaneDiffHunk, i: number) =>
+  changeBlocks(hunk).find((c) => c.firstRow === i);
+
+/** Per-block review controls (Undo / Keep), drawn in a bar under each change
+ *  block's last line. A context rather than a prop because lines render from
+ *  four places; `changes` is what the bar's "n of N" and its arrows walk. */
 const HunkActions = createContext<{
-  actions: (hunk: LaneDiffHunk) => ReactNode;
-  hunks: LaneDiffHunk[];
+  actions: (change: LaneDiffChange) => ReactNode;
+  changes: LaneDiffChange[];
   go: (index: number) => void;
 } | null>(null);
 
-/** Index of a hunk's last +/- line (unified), or last row with one (split). */
-function lastChangedLine(hunk: LaneDiffHunk) {
-  for (let i = hunk.lines.length - 1; i >= 0; i -= 1) {
-    if (hunk.lines[i]!.type !== "ctx") return i;
-  }
-  return -1;
-}
-function lastChangedRow(hunk: LaneDiffHunk) {
-  const rows = analyseHunk(hunk).rows;
-  for (let i = rows.length - 1; i >= 0; i -= 1) {
-    const r = rows[i]!;
-    if ((r.left && r.left.type !== "ctx") || (r.right && r.right.type !== "ctx")) return i;
-  }
-  return -1;
+/** File-wide index of `change`, for a row's `anchor`. */
+function useAnchor(change?: LaneDiffChange) {
+  const ctx = useContext(HunkActions);
+  return change && ctx ? ctx.changes.indexOf(change) : undefined;
 }
 
-/** The review bar: hangs just BELOW the last changed line, pinned to the
+/** The review bar: hangs just BELOW a change block's last line, pinned to the
  *  visible right edge, so it sits on the change it acts on — the editor-style
  *  "^ v 2 of 3 · Undo · Keep" instead of glyphs at the end of the `@@` line. */
-function HunkBar({ hunk }: { hunk: LaneDiffHunk }) {
+function HunkBar({ change }: { change: LaneDiffChange }) {
   const { t } = useTranslation(["lanes"]);
   const ctx = useContext(HunkActions);
   if (!ctx) return null;
-  const index = ctx.hunks.indexOf(hunk);
-  const total = ctx.hunks.length;
+  const index = ctx.changes.indexOf(change);
+  const total = ctx.changes.length;
   const nav =
     "rounded px-0.5 text-fg-muted hover:bg-surface-3 hover:text-fg-primary disabled:opacity-30";
   return (
@@ -370,14 +416,13 @@ function HunkBar({ hunk }: { hunk: LaneDiffHunk }) {
         <span className="px-0.5 tabular-nums text-fg-muted">
           {t("changes.hunkOf", { n: index + 1, total })}
         </span>
-        {ctx.actions(hunk)}
+        {ctx.actions(change)}
       </span>
     </span>
   );
 }
 
 function HunkHeader({ hunk, fixed }: { hunk: LaneDiffHunk; fixed?: boolean }) {
-  const ctx = useContext(HunkActions);
   const at = hunk.header.split("@@")[1];
   // Windowed, the header is one ROW_PX row like the lines around it.
   return (
@@ -387,7 +432,6 @@ function HunkHeader({ hunk, fixed }: { hunk: LaneDiffHunk; fixed?: boolean }) {
       }`}
       style={fixed ? FIXED : undefined}
       data-diff-item={fixed ? "" : undefined}
-      data-hunk-index={ctx ? ctx.hunks.indexOf(hunk) : undefined}
     >
       <span className="min-w-0 flex-1 truncate">
         {at ? `@@${at}@@` : hunk.header}
@@ -403,16 +447,20 @@ function UnifiedLine({
   emph,
   style,
   bar,
+  start,
 }: {
   line: LaneDiffLine;
   lang: string;
   emph?: [number, number];
   style?: CSSProperties;
-  /** This is the hunk's last changed line: hang the review bar under it. */
-  bar?: LaneDiffHunk;
+  /** This is a change block's last line: hang its review bar under it. */
+  bar?: LaneDiffChange;
+  /** This is a change block's first line: the bar's arrows scroll here. */
+  start?: LaneDiffChange;
 }) {
+  const anchor = useAnchor(start);
   return (
-    <Row tint={rowTint(line.type)} style={style}>
+    <Row tint={rowTint(line.type)} style={style} anchor={anchor}>
       <Gutter n={line.oldLine} />
       <Gutter n={line.newLine} />
       <span className="whitespace-pre px-2">
@@ -421,14 +469,13 @@ function UnifiedLine({
         </span>
         <Code text={line.text} lang={lang} emph={emph} />
       </span>
-      {bar && <HunkBar hunk={bar} />}
+      {bar && <HunkBar change={bar} />}
     </Row>
   );
 }
 
 function UnifiedHunk({ hunk, lang }: { hunk: LaneDiffHunk; lang: string }) {
   const { emph } = analyseHunk(hunk);
-  const last = lastChangedLine(hunk);
   return (
     <div>
       <HunkHeader hunk={hunk} />
@@ -438,7 +485,8 @@ function UnifiedHunk({ hunk, lang }: { hunk: LaneDiffHunk; lang: string }) {
           line={line}
           lang={lang}
           emph={emph.get(i)}
-          bar={i === last ? hunk : undefined}
+          bar={barAtLine(hunk, i)}
+          start={startAtLine(hunk, i)}
         />
       ))}
     </div>
@@ -473,16 +521,19 @@ function SplitLine({
   side,
   style,
   bar,
+  start,
 }: {
   row: PairRow;
   lang: string;
   side: "left" | "right";
   style?: CSSProperties;
-  bar?: LaneDiffHunk;
+  bar?: LaneDiffChange;
+  start?: LaneDiffChange;
 }) {
   const line = side === "left" ? row.left : row.right;
+  const anchor = useAnchor(start);
   return (
-    <Row tint={rowTint(line?.type ?? null)} style={style}>
+    <Row tint={rowTint(line?.type ?? null)} style={style} anchor={anchor}>
       <Gutter n={(side === "left" ? line?.oldLine : line?.newLine) ?? null} />
       <span className="whitespace-pre px-1">
         {line ? (
@@ -493,7 +544,7 @@ function SplitLine({
           />
         ) : null}
       </span>
-      {bar && <HunkBar hunk={bar} />}
+      {bar && <HunkBar change={bar} />}
     </Row>
   );
 }
@@ -519,8 +570,9 @@ function SplitColumn({
               row={row}
               lang={lang}
               side={side}
-              // One bar per hunk: on the right (new) column only.
-              bar={side === "right" && i === lastChangedRow(hunk) ? hunk : undefined}
+              // One bar per change block: on the right (new) column only.
+              bar={side === "right" ? barAtRow(hunk, i) : undefined}
+              start={startAtRow(hunk, i)}
             />
           ))}
         </div>
@@ -555,7 +607,8 @@ function SplitSlice({
               lang={lang}
               side={side}
               style={FIXED}
-              bar={side === "right" && i === lastChangedRow(hunk) ? hunk : undefined}
+              bar={side === "right" ? barAtRow(hunk, i) : undefined}
+              start={startAtRow(hunk, i)}
             />
           )
         )}
@@ -652,8 +705,8 @@ export function LaneDiffView({
   layout: DiffLayout;
   /** Take the parent's height (single-file view) instead of the 60vh cap. */
   fill?: boolean;
-  /** Controls drawn in each hunk's review bar. */
-  hunkActions?: (hunk: LaneDiffHunk) => ReactNode;
+  /** Controls drawn in each change block's review bar. */
+  hunkActions?: (change: LaneDiffChange) => ReactNode;
 }) {
   const root = useRef<HTMLDivElement>(null);
   const { t } = useTranslation(["lanes"]);
@@ -672,12 +725,15 @@ export function LaneDiffView({
     [layout, hunks]
   );
 
-  // The bar's arrows: bring hunk `index`'s header into view. A windowed
-  // unified diff may not have it in the DOM, so there it is found by offset.
+  const changes = useMemo(() => (hunks ? hunks.flatMap(changeBlocks) : []), [hunks]);
+  // The bar's arrows: bring change block `index`'s first line into view. A
+  // windowed unified diff may not have it in the DOM, so there it is found by
+  // offset.
   const go = (index: number) => {
     const el = root.current;
-    if (!el || !hunks) return;
-    const header = el.querySelector<HTMLElement>(`[data-hunk-index="${index}"]`);
+    const target = changes[index];
+    if (!el || !target) return;
+    const header = el.querySelector<HTMLElement>(`[data-change-index="${index}"]`);
     // The review list pins each file's header over its own diff.
     const sticky = el
       .closest("[data-review-file]")
@@ -688,10 +744,10 @@ export function LaneDiffView({
       return;
     }
     // Windowed: the header is not in the DOM, but its offset is known.
-    const at = items.findIndex((it) => it.i < 0 && it.hunk === hunks[index]);
+    const at = items.findIndex((it) => it.hunk === target.hunk && it.i === target.firstLine);
     if (at >= 0 && layout === "unified") el.scrollTop = at * ROW_PX;
   };
-  const review = hunkActions && hunks ? { actions: hunkActions, hunks, go } : null;
+  const review = hunkActions && hunks ? { actions: hunkActions, changes, go } : null;
 
   if (file.binary)
     return <p className="px-2 py-1 text-[10px] text-fg-muted">{t("changes.binary")}</p>;
@@ -727,7 +783,8 @@ export function LaneDiffView({
                     lang={lang}
                     emph={analyseHunk(hunk).emph.get(i)}
                     style={FIXED}
-                    bar={i === lastChangedLine(hunk) ? hunk : undefined}
+                    bar={barAtLine(hunk, i)}
+                    start={startAtLine(hunk, i)}
                   />
                 )
               )}
@@ -751,12 +808,16 @@ export function LaneFileView({
   lines,
   truncated,
   fill = false,
+  onEditAt,
 }: {
   path: string;
   lines: string[];
   truncated?: boolean;
   /** Take the parent's height instead of the 60vh cap. */
   fill?: boolean;
+  /** Set when the file is editable: a click on the text (0-based line, and
+   *  where the view was scrolled) asks to open the editor there. */
+  onEditAt?: (line: number, scrollTop: number) => void;
 }) {
   const { t } = useTranslation(["lanes"]);
   const lang = langFor(path);
@@ -765,9 +826,12 @@ export function LaneFileView({
   const minWidth = useMemo(() => `calc(${longest(lines)}ch + 3.5rem)`, [lines]);
   const row = (text: string, i: number, style?: CSSProperties) => (
     <Row key={i} tint="" style={style}>
-      <Gutter n={i + 1} />
-      <span className="whitespace-pre px-2">
-        <Code text={text} lang={lang} />
+      {/* `contents`: a line marker for the click handler, not a layout box. */}
+      <span data-ln={i} className="contents">
+        <Gutter n={i + 1} />
+        <span className="whitespace-pre px-2">
+          <Code text={text} lang={lang} />
+        </span>
       </span>
     </Row>
   );
@@ -775,7 +839,27 @@ export function LaneFileView({
     <div
       data-testid="lane-file-view"
       onScroll={(e) => win.onScroll(e.currentTarget)}
-      className={`overflow-auto font-mono text-[11px] leading-[1.45] ${boxHeight(fill, true)}`}
+      tabIndex={onEditAt ? 0 : undefined}
+      onClick={
+        onEditAt &&
+        ((e) => {
+          // A click that ends a drag-selection is copying, not asking to edit.
+          if (window.getSelection()?.toString()) return;
+          const ln = (e.target as HTMLElement).closest("[data-ln]")?.getAttribute("data-ln");
+          onEditAt(Number(ln ?? 0), e.currentTarget.scrollTop);
+        })
+      }
+      onKeyDown={
+        onEditAt &&
+        ((e) => {
+          if (e.key !== "Enter") return;
+          e.preventDefault();
+          onEditAt(0, e.currentTarget.scrollTop);
+        })
+      }
+      className={`overflow-auto font-mono text-[11px] leading-[1.45] ${boxHeight(fill, true)}${
+        onEditAt ? " cursor-text" : ""
+      }`}
     >
       {win.on ? (
         <Windowed count={lines.length} range={win.range} minWidth={minWidth}>

client/src/components/lanes/LaneStripCard.tsx

@@ -115,15 +115,18 @@ export default function LaneStripCard({
         <span className="shrink-0 text-[10px] font-semibold tracking-widest text-fg-muted">
           #{lane.id}
         </span>
-        <span className="truncate rounded bg-surface-4 px-1.5 py-0.5 text-fg-secondary">
-          {lane.stage}
-        </span>
-        {lane.tool === "codex" && (
+        {/* Codex lanes carry no pipeline, so no stage chip — the Codex tag
+            takes its place. */}
+        {lane.tool === "codex" ? (
           <span className="shrink-0 rounded border border-border bg-surface-2 px-1.5 py-0.5 text-[10px] text-fg-muted">
             Codex
           </span>
+        ) : (
+          <span className="truncate rounded bg-surface-4 px-1.5 py-0.5 text-fg-secondary">
+            {lane.stage}
+          </span>
         )}
-        {detectionLeads(lane) && (
+        {lane.tool !== "codex" && detectionLeads(lane) && (
           <span
             data-testid={`lane-tile-auto-${lane.id}`}
             title={lane.detected_signal || undefined}

client/src/components/lanes/__tests__/LaneChangesPanel.test.tsx

@@ -321,7 +321,7 @@ describe("LaneChangesPanel", () => {
     expect(screen.getByText("Staged Changes")).toBeInTheDocument();
   });
 
-  it("at full width shows the tree as a sidebar and opens a file straight into the editor", async () => {
+  it("at full width shows the tree as a sidebar and opens a file for reading, editing on a click", async () => {
     vi.mocked(api.lanes.gitTree).mockResolvedValue({
       available: true,
       path: "",
@@ -346,19 +346,24 @@ describe("LaneChangesPanel", () => {
     expect(screen.getAllByTestId("lane-changes-browse")).toHaveLength(1);
     await user.click(await within(sidebar).findByText("main.ts"));
 
-    // No Edit click: the editor is simply there, Save/Cancel idle until typed.
+    // Opening a file only shows it: no editor until the text itself is clicked.
+    const view = await screen.findByTestId("lane-file-view");
+    expect(screen.queryByTestId("lane-file-editor")).toBeNull();
+    expect(screen.queryByTestId("lane-file-edit")).toBeNull();
+    await user.click(view);
     const editor = await screen.findByTestId("lane-file-editor");
     expect(editor).toHaveValue("const whole = 1;");
-    expect(screen.queryByTestId("lane-file-edit")).toBeNull();
+    expect(editor).toHaveFocus();
     expect(screen.getByTestId("lane-file-save")).toBeDisabled();
     await user.type(editor, "x");
     expect(screen.getByTestId("lane-file-save")).toBeEnabled();
-    // Cancel reverts to the saved text and stays in the editor.
+    // Cancel drops the edit and goes back to reading.
     await user.click(screen.getByRole("button", { name: "Cancel" }));
-    expect(await screen.findByTestId("lane-file-editor")).toHaveValue("const whole = 1;");
+    expect(await screen.findByTestId("lane-file-view")).toHaveTextContent("const whole = 1;");
+    expect(screen.queryByTestId("lane-file-editor")).toBeNull();
   });
 
-  it("at full width opens a changed file from the overview straight into the editor", async () => {
+  it("at full width opens a changed file from the overview for reading, not editing", async () => {
     vi.mocked(api.lanes.gitFile).mockResolvedValue({
       available: true,
       path: "server/lib/git-ops.js",
@@ -372,10 +377,31 @@ describe("LaneChangesPanel", () => {
     render(<LaneChangesPanel laneId={7} full />);
     const list = await screen.findByTestId("lane-changes-overview");
     await user.click(within(list).getByText("server/lib/git-ops.js"));
-    expect(await screen.findByTestId("lane-file-editor")).toHaveValue("a");
-    expect(screen.queryByTestId("lane-file-edit")).toBeNull();
-    expect(screen.getByTestId("lane-file-save")).toBeDisabled();
-    expect(screen.getByRole("button", { name: "Cancel" })).toBeDisabled();
+    expect(await screen.findByTestId("lane-file-view")).toHaveTextContent("a");
+    expect(screen.queryByTestId("lane-file-editor")).toBeNull();
+  });
+
+  it("does not enter the editor when a click only ends a text selection", async () => {
+    vi.mocked(api.lanes.gitFile).mockResolvedValue({
+      available: true,
+      path: "server/lib/git-ops.js",
+      rev: "work",
+      binary: false,
+      truncated: false,
+      lines: ["copy me"],
+      sha: "b".repeat(40),
+    });
+    const user = userEvent.setup();
+    render(<LaneChangesPanel laneId={7} full />);
+    const list = await screen.findByTestId("lane-changes-overview");
+    await user.click(within(list).getByText("server/lib/git-ops.js"));
+    const view = await screen.findByTestId("lane-file-view");
+    const spy = vi.spyOn(window, "getSelection").mockReturnValue({
+      toString: () => "copy",
+    } as unknown as Selection);
+    await user.click(view);
+    spy.mockRestore();
+    expect(screen.queryByTestId("lane-file-editor")).toBeNull();
   });
 
   it("needs two clicks to discard, and only the second one reaches the server", async () => {
@@ -615,9 +641,7 @@ describe("LaneChangesPanel", () => {
     await user.click(screen.getByRole("button", { name: "Files" }));
     await user.type(await screen.findByLabelText("Find a file by path…"), "main");
     await user.click(await screen.findByText("src/main.ts"));
-    await screen.findByTestId("lane-file-view");
-
-    await user.click(screen.getByTestId("lane-file-edit"));
+    await user.click(await screen.findByTestId("lane-file-view"));
     const editor = await screen.findByTestId("lane-file-editor");
     expect(editor).toHaveValue("const whole = 1;");
     await user.clear(editor);
@@ -676,8 +700,7 @@ describe("LaneChangesPanel", () => {
     await user.click(screen.getByRole("button", { name: "Files" }));
     await user.type(await screen.findByLabelText("Find a file by path…"), "main");
     await user.click(await screen.findByText("src/main.ts"));
-    await screen.findByTestId("lane-file-view");
-    await user.click(screen.getByTestId("lane-file-edit"));
+    await user.click(await screen.findByTestId("lane-file-view"));
     await user.type(await screen.findByTestId("lane-file-editor"), "y");
     await user.click(screen.getByTestId("lane-file-save"));
 
@@ -922,6 +945,59 @@ describe("LaneChangesPanel", () => {
       expect(api.lanes.gitAction).toHaveBeenCalledWith(7, "stage-hunk", {
         path: "server/lib/git-ops.js",
         hunk: "@@ -9,2 +10,3 @@",
+        block: 0,
+        context: 3,
+      });
+    });
+
+    it("gives each +/- block inside ONE hunk its own bar and acts on that block only (#50)", async () => {
+      const user = userEvent.setup();
+      render(<LaneChangesPanel laneId={7} />);
+      await screen.findByTestId("lane-changes-overview");
+      vi.mocked(api.lanes.changes).mockResolvedValue(
+        changes({
+          files: [
+            {
+              path: "server/lib/git-ops.js",
+              status: " M",
+              untracked: false,
+              unstaged: true,
+              added: 2,
+              deleted: 1,
+              binary: false,
+              hunks: [
+                {
+                  header: "@@ -1,4 +1,5 @@",
+                  context: "",
+                  oldStart: 1,
+                  newStart: 1,
+                  lines: [
+                    { type: "del" as const, oldLine: 1, newLine: null, text: "a" },
+                    { type: "add" as const, oldLine: null, newLine: 1, text: "A" },
+                    { type: "ctx" as const, oldLine: 2, newLine: 2, text: "b" },
+                    { type: "ctx" as const, oldLine: 3, newLine: 3, text: "c" },
+                    { type: "add" as const, oldLine: null, newLine: 4, text: "new" },
+                    { type: "ctx" as const, oldLine: 4, newLine: 5, text: "d" },
+                  ],
+                },
+              ],
+            },
+          ],
+        })
+      );
+      await user.click(screen.getByRole("button", { name: "Review" }));
+      await screen.findByTestId("lane-changes-review");
+
+      const bars = screen.getAllByTestId("lane-hunk-bar");
+      expect(bars.map((b) => b.textContent)).toEqual([
+        expect.stringContaining("1 of 2"),
+        expect.stringContaining("2 of 2"),
+      ]);
+      await user.click(screen.getAllByRole("button", { name: "Stage this hunk" })[1]!);
+      expect(api.lanes.gitAction).toHaveBeenCalledWith(7, "stage-hunk", {
+        path: "server/lib/git-ops.js",
+        hunk: "@@ -1,4 +1,5 @@",
+        block: 1,
         context: 3,
       });
     });
@@ -959,6 +1035,7 @@ describe("LaneChangesPanel", () => {
       expect(api.lanes.gitAction).toHaveBeenCalledWith(7, "discard-hunk", {
         path: "server/lib/git-ops.js",
         hunk: "@@ -1,2 +1,3 @@",
+        block: 0,
         context: 3,
         confirm: true,
       });

client/src/components/lanes/__tests__/LaneDiffView.test.tsx

@@ -422,8 +422,8 @@ describe("LaneDiffView — hunk review bar navigation", () => {
     Object.defineProperty(scroller, "scrollHeight", { value: 1000 });
     Object.defineProperty(scroller, "clientHeight", { value: 100 });
     scroller.getBoundingClientRect = () => ({ top: 0 }) as DOMRect;
-    for (const el of view.container.querySelectorAll<HTMLElement>("[data-hunk-index]")) {
-      const k = Number(el.dataset.hunkIndex);
+    for (const el of view.container.querySelectorAll<HTMLElement>("[data-change-index]")) {
+      const k = Number(el.dataset.changeIndex);
       el.getBoundingClientRect = () => ({ top: k * 100 - scroller.scrollTop }) as DOMRect;
     }
     return scroller;
@@ -454,6 +454,49 @@ describe("LaneDiffView — hunk review bar navigation", () => {
     expect(screen.getAllByRole("button", { name: "Next change" })[2]).toBeDisabled();
   });
 
+  it("hangs one bar under EACH +/- block of a single hunk, in both layouts (#50)", () => {
+    const merged: LaneChangeFile = {
+      ...FILE,
+      hunks: [
+        {
+          header: "@@ -1,6 +1,6 @@",
+          context: "",
+          oldStart: 1,
+          newStart: 1,
+          lines: [
+            { type: "del" as const, oldLine: 1, newLine: null, text: "a" },
+            { type: "add" as const, oldLine: null, newLine: 1, text: "A" },
+            { type: "ctx" as const, oldLine: 2, newLine: 2, text: "b" },
+            { type: "del" as const, oldLine: 3, newLine: null, text: "c" },
+            { type: "ctx" as const, oldLine: 4, newLine: 3, text: "d" },
+            { type: "add" as const, oldLine: null, newLine: 4, text: "E" },
+            { type: "ctx" as const, oldLine: 5, newLine: 5, text: "f" },
+          ],
+        },
+      ],
+    };
+    const seen: number[] = [];
+    for (const layout of ["unified", "split"] as const) {
+      const { unmount } = render(
+        <LaneDiffView
+          file={merged}
+          layout={layout}
+          hunkActions={(c) => {
+            seen.push(c.block);
+            return <span />;
+          }}
+        />
+      );
+      expect(screen.getAllByTestId("lane-hunk-bar").map((b) => b.textContent)).toEqual([
+        expect.stringContaining("1 of 3"),
+        expect.stringContaining("2 of 3"),
+        expect.stringContaining("3 of 3"),
+      ]);
+      unmount();
+    }
+    expect(seen).toEqual([0, 1, 2, 0, 1, 2]);
+  });
+
   it("leaves an unwindowed review diff uncapped, so the panel is its only scroller", () => {
     render(<LaneDiffView file={three} layout="unified" />);
     expect(screen.getByTestId("lane-diff-view").className).not.toContain("max-h-[60vh]");

client/src/i18n/locales/en/lanes.json

@@ -256,6 +256,7 @@
   "changes.edit": "Edit",
   "changes.save": "Save",
   "changes.cancelEdit": "Cancel",
+  "changes.clickToEdit": "Click the text to edit",
   "changes.editorLabel": "Edit {{path}}",
   "changes.prevHunk": "Previous change",
   "changes.nextHunk": "Next change",

client/src/i18n/locales/vi/lanes.json

@@ -256,6 +256,7 @@
   "changes.edit": "Sửa",
   "changes.save": "Lưu",
   "changes.cancelEdit": "Huỷ",
+  "changes.clickToEdit": "Bấm vào nội dung để sửa",
   "changes.editorLabel": "Sửa {{path}}",
   "changes.prevHunk": "Thay đổi trước",
   "changes.nextHunk": "Thay đổi sau",

client/src/lib/api.ts

@@ -2572,6 +2572,8 @@ export const api = {
         paths?: string[];
         path?: string;
         hunk?: string;
+        /** One change block (a run of +/- lines) inside `hunk`, by index. */
+        block?: number;
         context?: number;
         confirm?: boolean;
         /** resolve: which side wins, or `done` for a hand-edited file. */

client/src/pages/Workspace.tsx

@@ -523,6 +523,7 @@ export function Workspace() {
   }, [refreshList]);
 
   const currentLane = selectedLaneId !== null ? lanes.find((l) => l.id === selectedLaneId) : null;
+  const isCodexLane = currentLane?.tool === "codex";
 
   // Feature list follows the selected lane, resets the viewer on lane switch.
   useEffect(() => {
@@ -815,40 +816,52 @@ export function Workspace() {
                     <Pencil className="h-3 w-3 shrink-0 text-fg-muted opacity-0 transition-opacity group-hover:opacity-100" />
                   </button>
                 )}
-                <span className="shrink-0 tabular-nums text-xs text-fg-muted">
-                  {since(currentLane.stage_seconds)}
-                </span>
+                {/* Codex lanes carry no pipeline: no time-at-stage, no pipeline
+                    or feature picker, no map. */}
+                {!isCodexLane && (
+                  <span className="shrink-0 tabular-nums text-xs text-fg-muted">
+                    {since(currentLane.stage_seconds)}
+                  </span>
+                )}
                 {showInfo && (
                   <>
-                    <select
-                      data-testid="pipeline-picker"
-                      aria-label={tLanes("pipelinePicker.label")}
-                      className="rounded border border-border bg-surface-1 px-2 py-0.5 text-xs text-fg-secondary disabled:opacity-60"
-                      value={currentLane.pipeline}
-                      disabled={!!viewedFeature}
-                      title={
-                        viewedFeature
-                          ? tLanes("features.viewingArchived", { slug: viewedFeature.slug })
-                          : undefined
-                      }
-                      onChange={(e) => void handlePipelineChange(currentLane.id, e.target.value)}
-                    >
-                      {(pipelineTemplates.length
-                        ? pipelineTemplates
-                        : [{ id: currentLane.pipeline, name: currentLane.pipeline_name, nodes: [] }]
-                      ).map((p) => (
-                        <option key={p.id} value={p.id}>
-                          {p.nodes.length ? `${p.name} (${p.nodes.length})` : p.name}
-                        </option>
-                      ))}
-                    </select>
+                    {!isCodexLane && (
+                      <select
+                        data-testid="pipeline-picker"
+                        aria-label={tLanes("pipelinePicker.label")}
+                        className="rounded border border-border bg-surface-1 px-2 py-0.5 text-xs text-fg-secondary disabled:opacity-60"
+                        value={currentLane.pipeline}
+                        disabled={!!viewedFeature}
+                        title={
+                          viewedFeature
+                            ? tLanes("features.viewingArchived", { slug: viewedFeature.slug })
+                            : undefined
+                        }
+                        onChange={(e) => void handlePipelineChange(currentLane.id, e.target.value)}
+                      >
+                        {(pipelineTemplates.length
+                          ? pipelineTemplates
+                          : [
+                              {
+                                id: currentLane.pipeline,
+                                name: currentLane.pipeline_name,
+                                nodes: [],
+                              },
+                            ]
+                        ).map((p) => (
+                          <option key={p.id} value={p.id}>
+                            {p.nodes.length ? `${p.name} (${p.nodes.length})` : p.name}
+                          </option>
+                        ))}
+                      </select>
+                    )}
                     <LaneRouterRow lane={currentLane} />
                     {/* No stage chip and no "auto: <stage>" chip here: the
                         PipelineMap right below this header already draws both
                         — the declared node as the current ring, the detected
                         one as its amber badge — so the chips were a second,
                         smaller copy of the same two facts. */}
-                    {features.length > 0 && (
+                    {!isCodexLane && features.length > 0 && (
                       <select
                         data-testid="feature-picker"
                         className="rounded border border-border bg-surface-1 px-2 py-0.5 text-xs"
@@ -908,19 +921,21 @@ export function Workspace() {
                     onSelectLane={setSelectedLaneId}
                   />
                 </div>
-                <div className="mb-3">
-                  <PipelineMap
-                    nodes={
-                      viewedFeature ? viewedFeature.pipeline_nodes : currentLane.pipeline_nodes
-                    }
-                    detectedSignal={viewedFeature ? undefined : currentLane.detected_signal}
-                  />
-                  {viewedFeature && (
-                    <p data-testid="feature-viewer-banner" className="mb-2 text-xs text-fg-muted">
-                      {tLanes("features.viewingArchived", { slug: viewedFeature.slug })}
-                    </p>
-                  )}
-                </div>
+                {!isCodexLane && (
+                  <div className="mb-3">
+                    <PipelineMap
+                      nodes={
+                        viewedFeature ? viewedFeature.pipeline_nodes : currentLane.pipeline_nodes
+                      }
+                      detectedSignal={viewedFeature ? undefined : currentLane.detected_signal}
+                    />
+                    {viewedFeature && (
+                      <p data-testid="feature-viewer-banner" className="mb-2 text-xs text-fg-muted">
+                        {tLanes("features.viewingArchived", { slug: viewedFeature.slug })}
+                      </p>
+                    )}
+                  </div>
+                )}
                 {proofFeature &&
                   (Object.keys(proofFeature.groups).length > 0 || proofFeature.ticket_report) && (
                     <div data-testid="proof-gallery" className="mt-2">