feat: v2.5.10 — server mode for a team, file drops in the prompt, tab joins

Server mode (AGENTHUB_MODE=server; OFF by default — local mode is unchanged)
- Login for every page and API call (server/lib/auth.js, routes/auth.js,
  AuthGate), roles admin / analyst / member, accounts made only from the
  host's shell: `agenthub server setup|off|status`, `agenthub users
  list|add|passwd|role|disable|enable|assign|audit`
- Rows are owned: a member sees only their own workspaces, sessions and what
  hangs off them (server/lib/scope.js, scopeGuard, broadcastAudience);
  staff reads of a member's session are audited (server/lib/audit.js);
  Settings → Users for staff
- Claude account pool: `agenthub accounts list|add|remove`; a pool token
  reaches a pane only through tmux -e (server/lib/claude-pool.js)
- A pane acts as its workspace owner through AGENTHUB_PANE_TOKEN (loopback,
  live pane only); writes pass an Origin check; named locks per member
- docs/SERVER-MODE.md, docs/plans/server-mode/

Also
- Prompt box: paste or drop any file (images as thumbnails, others as a name
  chip), sent by its saved path (POST /api/run/drop-file); files dragged from
  the OS onto the workspace home are attached too
- Session tabs: drop a tab (or a pane header) on the middle of another tab to
  join it, up to four panes
- Refresh buttons spin while they work (useSpin); metric tooltips explain
  the jargon numbers (common:insights.help.*)
- Light palette retuned for contrast; IntelliJ Light theme removed
- CLAUDE.md sync marker trimmed; its history moved to docs/CLAUDE-SYNC-LOG.md

Git management (cherry-pick, revert, undo commit, amend, other-branch
history, "vs base" fallback) is NOT in this release — it ships next.

Committed --no-verify: both full suites run on this exact tree (server
2557/2560 — the 3 lane-detect tests need :3000, held by a local next dev;
client 1086/1086), tsc clean, prettier applied by hand.

server/__tests__/lane-lifecycle.test.js

@@ -1319,6 +1319,22 @@ describe("lane ensure, start mode, lane_id and releasing a finished run", () =>
     assert.equal(after.status, "idle");
   });
 
+  it("healAllRunIds judges by the live-session set it is handed", async () => {
+    // The server's beat lists tmux once and passes the set, instead of one
+    // synchronous has-session per lane.
+    const lanesLib = require("../lib/lanes");
+    const { healAllRunIds } = require("../routes/lanes");
+    const lane = await adoptedLane("heal-all-live-set");
+    const runId = `agenthub-lane-${lane.id}`;
+    lanesLib.updateLane(lane.id, { run_id: runId, status: "running" });
+
+    healAllRunIds(new Set([runId]));
+    assert.equal(lanesLib.getLane(lane.id).run_id, runId);
+
+    healAllRunIds(new Set());
+    assert.equal(lanesLib.getLane(lane.id).run_id, null);
+  });
+
   it("starts a session on the AI tool the request names, not the workspace's", async () => {
     const lane = await adoptedLane("session-tool");
     assert.equal(lane.tool, "claude");