feat(lanes): reorder and rename lane cards, and show each file's line delta

The lane strip's tiles are now drag-reorderable (Alt+←/→ is the keyboard
path), and a lane's name can be set in place from the detail header. The
"Lane 23 ·" prefix is gone from both — the bare `#23` stays on the tile,
because that number is how the CLI addresses a lane.

Card order is a per-viewer preference, not a lane fact: it lives in
localStorage (`agenthub.workspace.laneOrder`) beside the split-view layout
and writes nothing server-side, so `GET /api/lanes` and `agenthub lanes`
keep answering in id order. Renaming is the opposite — it is PATCH
/api/lanes/:id with {title}, the one lane column a user now types into
directly.

That made a patch value reachable by hand for the first time, so
`bindable` now rejects any non-scalar for every PATCHABLE column with
EBADFIELD, and the route answers 400 for that and for the
SQLITE_CONSTRAINT family, rather than handing better-sqlite3 a datatype
throw and reporting 500 on plain bad input.

The uncommitted-files tooltip became a real panel. `GET /api/lanes/:id/git`
now returns `files` as {path, status, added, deleted} records — deltas from
one `git diff --numstat HEAD`, null where git has none to report (untracked,
binary, renamed) — and the card renders them portalled to the body, so the
Workspace's own scroll box cannot clip the list.

client/src/components/lanes/LaneCard.tsx

@@ -19,17 +19,18 @@
  * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
  */
 
-import { useEffect, useState } from "react";
+import { useCallback, useEffect, useLayoutEffect, useRef, useState } from "react";
+import { createPortal } from "react-dom";
 import { useTranslation } from "react-i18next";
 import { DestructiveLaneModal } from "./DestructiveLaneModal";
 import { api } from "../../lib/api";
 import { eventBus } from "../../lib/eventBus";
 import { keepIfSame } from "../../lib/keepIfSame";
 import type { AiRouter } from "../../lib/api";
-import type { Lane, LaneGitFacts, LaneRuntime, NamedLock } from "../../lib/types";
+import type { Lane, LaneGitFacts, LaneGitFile, LaneRuntime, NamedLock } from "../../lib/types";
 
 /** How often a mounted card re-reads its working-copy facts. Slow on purpose:
- *  each call is three git subprocesses server-side, and a branch name does not
+ *  each call is five git subprocesses server-side, and a branch name does not
  *  change on the timescale the lane list is polled at. */
 const GIT_REFRESH_MS = 30_000;
 
@@ -379,6 +380,141 @@ export function LaneToolsMenu({ lane }: { lane: Lane }) {
   );
 }
 
+/** Porcelain status code -> the letter shown and the colour it is shown in.
+ *  Keyed on the code's first meaningful character, so an index-side change
+ *  (`M `), a worktree-side one (` M`) and both (`MM`) read the same. */
+const GIT_STATUS_STYLE: Record<string, string> = {
+  M: "text-status-warning",
+  A: "text-status-success",
+  D: "text-status-danger",
+  R: "text-accent",
+  C: "text-accent",
+  U: "text-status-danger",
+  "?": "text-fg-muted",
+};
+
+/**
+ * The file list behind a lane's uncommitted counts: which files, what happened
+ * to each, and how many lines it gained and lost.
+ *
+ * It replaced a native `title` tooltip, which could show the same paths but
+ * neither colour them nor align the deltas — and a plain porcelain dump is not
+ * something you read at a glance.
+ *
+ * PORTALLED to `document.body` and `position: fixed`, for the same reason this
+ * file's own header says the tools dropdown was moved out of the card: a lane
+ * card renders inside the Workspace's `max-h-[45vh] overflow-y-auto` box, and
+ * an absolutely positioned panel would be clipped by it for every card that is
+ * not at the very top. It flips above its anchor rather than off the bottom of
+ * the window, and clamps to the right edge.
+ */
+function LaneGitFilesPanel({
+  files,
+  hidden,
+  anchor,
+  onPointerEnter,
+  onPointerLeave,
+}: {
+  files: LaneGitFile[];
+  hidden: number;
+  /** The counts button this panel hangs off. */
+  anchor: HTMLElement | null;
+  onPointerEnter: () => void;
+  onPointerLeave: () => void;
+}) {
+  const { t } = useTranslation(["lanes"]);
+  const panelRef = useRef<HTMLDivElement>(null);
+  const [pos, setPos] = useState<{ top: number; left: number } | null>(null);
+
+  // After the first paint, when the panel's real height is known: place it
+  // under the anchor, or above it when that would run off the bottom.
+  useLayoutEffect(() => {
+    if (!anchor || !panelRef.current) return;
+    const a = anchor.getBoundingClientRect();
+    const p = panelRef.current.getBoundingClientRect();
+    const gap = 4;
+    const top =
+      a.bottom + gap + p.height > window.innerHeight ? a.top - p.height - gap : a.bottom + gap;
+    setPos({
+      top: Math.max(8, top),
+      left: Math.max(8, Math.min(a.left, document.documentElement.clientWidth - p.width - 8)),
+    });
+  }, [anchor, files]);
+  // Totals are over the LISTED files only — the cap means the rest are unknown,
+  // and a total that silently omits them would be a wrong number rather than a
+  // partial one. `hidden` says how many are missing.
+  const added = files.reduce((n, f) => n + (f.added ?? 0), 0);
+  const deleted = files.reduce((n, f) => n + (f.deleted ?? 0), 0);
+
+  return createPortal(
+    <div
+      ref={panelRef}
+      data-testid="lane-git-files"
+      role="group"
+      aria-label={t("git.filesHeading", { count: files.length })}
+      // The pointer has to be able to travel INTO the panel to scroll it, so
+      // the panel answers the same enter/leave pair the trigger does.
+      onMouseEnter={onPointerEnter}
+      onMouseLeave={onPointerLeave}
+      style={{
+        position: "fixed",
+        zIndex: 60,
+        top: pos?.top ?? 0,
+        left: pos?.left ?? 0,
+        // Hidden for the one frame before it has been measured, so it never
+        // flashes at the top-left corner.
+        visibility: pos ? "visible" : "hidden",
+      }}
+      className="max-h-72 w-[22rem] max-w-[calc(100vw-1rem)] overflow-y-auto rounded-md border border-border bg-surface-1 p-2 shadow-lg"
+    >
+      <div className="mb-1.5 flex items-baseline gap-2 border-b border-border pb-1.5 text-[11px]">
+        <span className="text-fg-secondary">{t("git.filesHeading", { count: files.length })}</span>
+        <span className="ml-auto shrink-0 font-mono tabular-nums">
+          <span className="text-status-success">+{added}</span>{" "}
+          <span className="text-status-danger">−{deleted}</span>
+        </span>
+      </div>
+      <ul className="space-y-0.5 font-mono text-[11px]">
+        {files.map((f) => {
+          const code = f.status.trim()[0] || "?";
+          return (
+            <li key={f.path} className="flex items-baseline gap-2">
+              <span
+                className={`w-3 shrink-0 font-semibold ${GIT_STATUS_STYLE[code] || "text-fg-muted"}`}
+                title={f.status}
+              >
+                {code}
+              </span>
+              {/* The DIRECTORY truncates, never the filename: the name is what
+                  you scan for, the path is only there to disambiguate it. */}
+              <span className="flex min-w-0 flex-1 items-baseline" title={f.path}>
+                <span className="truncate text-fg-muted">{f.path.replace(/[^/]+$/, "")}</span>
+                <span className="shrink-0 text-fg-primary">{f.path.split("/").pop()}</span>
+              </span>
+              <span className="shrink-0 tabular-nums">
+                {f.added === null && f.deleted === null ? (
+                  <span className="text-fg-muted">{t("git.noDelta")}</span>
+                ) : (
+                  <>
+                    <span className="text-status-success">+{f.added ?? 0}</span>{" "}
+                    <span className="text-status-danger">−{f.deleted ?? 0}</span>
+                  </>
+                )}
+              </span>
+            </li>
+          );
+        })}
+      </ul>
+      {hidden > 0 && (
+        <p className="mt-1.5 border-t border-border pt-1.5 text-[10px] text-fg-muted">
+          {t("git.filesMore", { count: hidden })}
+        </p>
+      )}
+    </div>,
+    document.body
+  );
+}
+
 export default function LaneCard({
   lane,
   onAction,
@@ -399,6 +535,21 @@ export default function LaneCard({
   const [menuOpen, setMenuOpen] = useState(false);
   const [runtimeBump, setRuntimeBump] = useState(0);
   const [bootLine, setBootLine] = useState<string | null>(null);
+  const [filesOpen, setFilesOpen] = useState(false);
+  const [countsAnchor, setCountsAnchor] = useState<HTMLButtonElement | null>(null);
+  // Closing is DELAYED: the panel is portalled away from the trigger, so the
+  // pointer leaves the trigger before it can land on the panel it is heading
+  // for. Any enter — trigger or panel — cancels the pending close.
+  const filesCloseTimer = useRef<number | undefined>(undefined);
+  const openFiles = useCallback(() => {
+    window.clearTimeout(filesCloseTimer.current);
+    setFilesOpen(true);
+  }, []);
+  const closeFiles = useCallback(() => {
+    window.clearTimeout(filesCloseTimer.current);
+    filesCloseTimer.current = window.setTimeout(() => setFilesOpen(false), 150);
+  }, []);
+  useEffect(() => () => window.clearTimeout(filesCloseTimer.current), []);
   const git = useLaneGitFacts(lane.id);
   const runtime = useLaneRuntime(lane.id, runtimeBump);
   const locks = useLaneLocks(lane.slot);
@@ -530,31 +681,42 @@ export default function LaneCard({
             sentence rather than a four-row block. The cwd is NOT here — the
             lane-detail header above this card already spells it out. */}
         {git?.available && (
-          <div
-            data-testid="lane-git"
-            className="mb-2 flex items-baseline gap-2 truncate font-mono text-[11px] text-fg-secondary"
-            title={git.subject}
-          >
-            <span className="shrink-0">⑂ {git.branch}</span>
-            <span className="shrink-0 text-fg-muted">{git.head}</span>
-            <span className="truncate text-fg-muted">{git.subject}</span>
-            {(git.dirty > 0 || git.untracked > 0) && (
-              <span
-                className="shrink-0 cursor-help text-status-warning/80"
-                /* Native title: the counts' own file list, capped server-side.
-                   A hover card would need a portal to escape this truncating
-                   row — the browser's tooltip already escapes it for free. */
-                title={
-                  git.files?.length
-                    ? git.files.join("\n") +
-                      (git.dirty + git.untracked > git.files.length
-                        ? `\n… +${git.dirty + git.untracked - git.files.length}`
-                        : "")
-                    : undefined
-                }
-              >
-                {t("git.uncommitted", { dirty: git.dirty, untracked: git.untracked })}
-              </span>
+          <div className="mb-2">
+            <div
+              data-testid="lane-git"
+              className="flex items-baseline gap-2 truncate font-mono text-[11px] text-fg-secondary"
+              title={git.subject}
+            >
+              <span className="shrink-0">⑂ {git.branch}</span>
+              <span className="shrink-0 text-fg-muted">{git.head}</span>
+              <span className="truncate text-fg-muted">{git.subject}</span>
+              {(git.dirty > 0 || git.untracked > 0) && (
+                <button
+                  type="button"
+                  ref={setCountsAnchor}
+                  data-testid="lane-git-counts"
+                  aria-expanded={filesOpen}
+                  onMouseEnter={openFiles}
+                  onMouseLeave={closeFiles}
+                  // Focus and click open it too: hover is not a gesture a
+                  // keyboard or a touchscreen has.
+                  onFocus={openFiles}
+                  onBlur={closeFiles}
+                  onClick={() => setFilesOpen((v) => !v)}
+                  className="shrink-0 cursor-help text-status-warning/80 underline decoration-dotted underline-offset-2"
+                >
+                  {t("git.uncommitted", { dirty: git.dirty, untracked: git.untracked })}
+                </button>
+              )}
+            </div>
+            {filesOpen && git.files?.length > 0 && (
+              <LaneGitFilesPanel
+                files={git.files}
+                hidden={git.dirty + git.untracked - git.files.length}
+                anchor={countsAnchor}
+                onPointerEnter={openFiles}
+                onPointerLeave={closeFiles}
+              />
             )}
           </div>
         )}