feat(lanes): name the files behind a lane's uncommitted counts

GET /api/lanes/:id/git now returns `files`, the raw `git status --porcelain`
lines the dirty/untracked counts were already parsed from, capped at 20 so a
lane mid-`npm install` cannot ship thousands of paths through a polled
endpoint. The lane card hovers them as the tooltip on its
"N modified · N untracked" text, appending "… +N" when the cap bit.

No new subprocess and no new endpoint — statusCounts was counting those lines
and throwing them away.

client/src/components/lanes/LaneCard.tsx

@@ -539,7 +539,20 @@ export default function LaneCard({
             <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 text-status-warning/80">
+              <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>
             )}

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

@@ -207,6 +207,7 @@ describe("LaneCard git block", () => {
     subject: "free-text rule mode in the form",
     dirty: 2,
     untracked: 1,
+    files: [" M server/lib/alerts.js", " M client/src/lib/api.ts", "?? scratch.txt"],
   };
 
   it("renders the live branch, head, subject and uncommitted counts", async () => {
@@ -218,6 +219,10 @@ describe("LaneCard git block", () => {
     expect(block.textContent).toContain("9b3e74a");
     expect(block.textContent).toContain("free-text rule mode in the form");
     expect(block.textContent).toContain("2");
+    // Hovering the counts names the files behind them.
+    expect(screen.getByText(/modified/).title).toBe(
+      " M server/lib/alerts.js\n M client/src/lib/api.ts\n?? scratch.txt"
+    );
     // The live branch replaces the lane's recorded one rather than doubling it.
     expect(screen.queryByText(/stale\/recorded/)).toBeNull();
   });

client/src/lib/types.ts

@@ -2592,6 +2592,8 @@ export type LaneGitFacts =
       dirty: number;
       /** Files git has never seen. */
       untracked: number;
+      /** Raw `git status --porcelain` lines, capped; the counts stay exact. */
+      files: string[];
     }
   | { available: false };
 

docs/LANES.md

@@ -370,7 +370,9 @@ A missing source `.env` falls back to `.env.example` with a loud warning, never
 
 The dashboard web UI merges lanes and runs into a single **Workspace** page accessible at `/run` (the old `/lanes` route now redirects here). Top to bottom:
 
-- **Header** — the page title and four counters (`lanes`, `running`, `needs you`, `dead`), plus Add lane. The `needs you` and `dead` counters appear only when they are non-zero, so a quiet header means nothing is waiting on a human.
+- **No page header.** The page title and the four counters (`lanes`, `running`, `needs you`, `dead`) are gone: the lane strip below already shows every lane with its own liveness dot and its ⚠ marker, so the counters restated it a row higher and cost height on a screen whose point is the terminal. `GET /api/lanes` still returns `counts` for other callers.
+- **Lane strip** — the horizontally scrolling row of lane tiles. Its FIRST tile is **Add lane** (dashed border, no liveness dot), not a header button: creating a lane is the same kind of act as picking one, so it reads as the empty slot at the head of the row.
+- **Lane-detail header row** — one row, and every per-lane control lives on it: liveness + status, the lane's name, time-on-stage, the pipeline picker, the Model (AI Router) select, stage badges, the feature picker, and on the right the **Tools** menu (agents install / mcp sync / sync-base check, hidden when the lane declares no runtime profile), the info toggle, the split-view toggle and Remove. Tools sits here rather than in Settings because all three of its actions run against one lane's `cwd` — in Settings it would need a lane picker just to say which.
 - **Detail panel** — the selected lane's declared stage, its inferred stage when detection leads, a full-width pipeline map, and a legend naming all five node states plus the dashed-amber inferred treatment.
 - **Terminal** — a real interactive terminal (xterm.js) displaying the tmux session's PTY output, with full support for interactive commands, editors, and pagers. A live run keeps its rendered history and scroll position when scrolling.
 - **Split view** — a layout toggle (one pane / two side by side / a 2×2 grid, drawn as icons rather than the words, with the count kept as each button's `aria-label` and tooltip) renders that many independent terminal panes side by side (`grid-cols-2` for 2, a 2×2 grid for 4). Layout 1 is bound to the lane strip's selection, same as always; layouts 2 and 4 give each pane its own lane picker, independent of the strip. The chosen layout and each pane's lane persist to `localStorage` (`agenthub.workspace.splitView`) across reloads.
@@ -442,7 +444,8 @@ curl http://localhost:4820/api/lanes/5/git
   "head": "9b3e74a",
   "subject": "free-text rule mode in the form",
   "dirty": 2,
-  "untracked": 1
+  "untracked": 1,
+  "files": [" M server/lib/alerts.js", " M client/src/lib/api.ts", "?? scratch.txt"]
 }
 ```
 
@@ -451,6 +454,11 @@ curl http://localhost:4820/api/lanes/5/git
   is a normal state, not a fault, and the card simply renders without a git row.
 - A detached checkout reports the literal `HEAD` that git returns, rather than a
   prettier invention.
+- `files` holds the raw `git status --porcelain` lines the two counts came from,
+  **capped at 20** — the card hovers them as a tooltip on the
+  `N modified · N untracked` text, and a lane mid-`npm install` would otherwise
+  ship thousands of paths through a polled endpoint. The counts are never
+  capped, so the tooltip appends `… +N` when it is showing less than all of it.
 - An unknown lane id is a `404`.
 
 This is **not** folded into `GET /api/lanes` on purpose: it shells out to git

openapi.yaml

@@ -10700,7 +10700,7 @@ paths:
             type: integer
       responses:
         '200':
-          description: available:true with {branch, head, subject, dirty, untracked}, or available:false alone.
+          description: available:true with {branch, head, subject, dirty, untracked, files}, or available:false alone. files holds the raw `git status --porcelain` lines behind those counts, capped at 20; the counts themselves are never capped.
         '404':
           description: Lane not found.
   /api/lanes/{id}/runtime:

server/__tests__/worktree.test.js

@@ -100,6 +100,8 @@ describe("worktree", () => {
     assert.equal(s.dirty, 1);
     assert.equal(s.untracked, 1); // node_modules is ignored, so it does not count
     assert.match(s.head, /^[0-9a-f]{7,40}$/);
+    // The same lines the counts came from, so a caller can name the files.
+    assert.deepEqual(s.files.sort(), [" M README.md", "?? scratch.txt"]);
     // The fixture has no remotes. Given the lane's base branch, unpushedCount
     // measures base..HEAD — this worktree has committed nothing of its own, so 0.
     assert.equal(await wt.unpushedCount(dir, "main"), 0);

server/lib/worktree.js

@@ -16,6 +16,8 @@ const execFileAsync = promisify(execFile);
 
 const LANES_ROOT = process.env.LANES_ROOT || path.join(os.homedir(), ".claude", "agenthub-lanes");
 const PROTECTED_BRANCHES = new Set(["main", "master"]);
+/** Most status lines `statusCounts` reports by name; the counts stay exact. */
+const STATUS_FILE_CAP = 20;
 
 /**
  * Promisified git wrapper. On failure, throws an Error with err.git = { args, code, stderr }.
@@ -549,11 +551,16 @@ async function removeWorktree(lane) {
 /**
  * Parse git status --porcelain to count dirty, untracked, and get HEAD commit.
  * Lines starting with ?? are untracked; others are dirty.
+ *
+ * `files` carries the same lines back verbatim so a caller can show WHICH
+ * files the counts mean, capped because this rides a polled endpoint and a
+ * lane mid-`npm install` can report thousands.
  */
 async function statusCounts(dir) {
   const result = await git(dir, ["status", "--porcelain=v1", "--untracked-files=normal"]);
   let dirty = 0;
   let untracked = 0;
+  const files = [];
 
   for (const line of result.stdout.split("\n")) {
     if (!line.trim()) continue;
@@ -562,13 +569,14 @@ async function statusCounts(dir) {
     } else {
       dirty++;
     }
+    if (files.length < STATUS_FILE_CAP) files.push(line.trimEnd());
   }
 
   // Get short commit hash
   const headResult = await git(dir, ["rev-parse", "--short", "HEAD"]);
   const head = headResult.stdout.trim();
 
-  return { dirty, untracked, head };
+  return { dirty, untracked, head, files };
 }
 
 /**
@@ -581,10 +589,10 @@ async function statusCounts(dir) {
  * caller shows what git says rather than inventing a nicer word for it.
  */
 async function gitFacts(dir) {
-  const { dirty, untracked, head } = await statusCounts(dir);
+  const { dirty, untracked, head, files } = await statusCounts(dir);
   const branch = (await git(dir, ["rev-parse", "--abbrev-ref", "HEAD"])).stdout.trim();
   const subject = (await git(dir, ["log", "-1", "--format=%s"])).stdout.trim();
-  return { branch, head, subject, dirty, untracked };
+  return { branch, head, subject, dirty, untracked, files };
 }
 
 /**

server/openapi-extra/lanes.js

@@ -274,7 +274,7 @@ const paths = {
       responses: {
         200: {
           description:
-            "available:true with {branch, head, subject, dirty, untracked}, or available:false alone.",
+            "available:true with {branch, head, subject, dirty, untracked, files}, or available:false alone. files holds the raw `git status --porcelain` lines behind those counts, capped at 20; the counts themselves are never capped.",
         },
         404: { description: "Lane not found." },
       },