feat(settings): one page per section with a grouped nav and search

Settings moves from a tab bar to /settings/<section>: a left nav grouped
General / Agents / Routing / Git / Projects (a select on narrow screens), a
search box over every section (Ctrl/Cmd+F, Enter opens the first match), and
row primitives. Each AI tool has its page under agents/<id>, the AI Tools
modal becomes the Agents page, Pricing shows every vendor, Git → Worktrees
sets which untracked worktrees the sidebar lists, and each project gets a
page with its own worktree override and Forget all. ?tool= and #ai-tools
links redirect to the path form.

docs/LANES.md

@@ -392,7 +392,8 @@ The dashboard web UI merges workspaces and runs into a single **Workspace** page
 - **No page header.** The page title and the four counters (`lanes`, `running`, `needs you`, `dead`) are gone: the sidebar's project tree shows every workspace with its own status dot, and the status bar at the bottom of every page counts running and need-you workspaces. `GET /api/lanes` still returns `counts` for other callers.
 - **The sidebar's project tree picks the workspace** — on every page, between the nav and the footer (`client/src/components/ProjectTree.tsx`). Workspaces are grouped under **Projects**: one per git repository, keyed by the repo's MAIN worktree root, with every workspace outside a repo under **Folders** (last). The grouping comes from `GET /api/projects` (see `docs/API.md`), read when the set of workspaces changes or on the header's Refresh — never on every status frame, so it shells out to git only then, and caches what it read. A row (`WorkspaceRow.tsx`) shows a status dot (green = active, pulsing while running; amber row = needs you; red = dead or error; grey = idle), the title or folder name, a `primary` badge on the repo's own root, the branch (or the path relative to the repo), the tool's icon and the id as `#23` — the number the CLI addresses it by. Clicking a row opens `/workspace?lane=<id>`: the URL is the selection, so a notification link, F5 and the back button all land on the same workspace, and a bare `/workspace` reopens the last one shown (`agenthub.workspace.selected`) or the first. The project's `+` opens the Add-workspace modal prefilled with that repo; the PROJECTS header has Refresh and a plain `+`. In the collapsed rail the tree is a single icon that opens the sidebar.
 - **Row menu** — right-click a row, or its `⋯` button: Start/Stop (slot 0), Rename, the Model (AI Router) select, Create/update readme file (Claude only), New workspace here…, Copy path, Reset worktree… (managed only) and Delete workspace…, each the call the rest of the UI already makes. Delete is record-only exactly as before (see "Removing a workspace").
-- **Untracked worktrees** — a repo's worktrees that no workspace sits on (from `git worktree list`) are listed dimmed under the project, with **Adopt** (`POST /api/lanes/ensure {exact: true}` with the default AI tool, then selected). Shown by default; the tree's preferences (`agenthub.sidebar.projects` in `localStorage`: collapsed projects, `showUntracked`, hidden sources `claude` = `<repo>/.claude/worktrees/*` and `agenthub` = `LANES_ROOT`) can hide them, and the project row then says "N hidden" — a click shows them for this visit.
+- **Untracked worktrees** — a repo's worktrees that no workspace sits on (from `git worktree list`) are listed dimmed under the project, with **Adopt** (`POST /api/lanes/ensure {exact: true}` with the default AI tool, then selected). Shown by default; the tree's preferences (`agenthub.sidebar.projects` in `localStorage`: collapsed projects, `showUntracked`, hidden sources `claude` = `<repo>/.claude/worktrees/*` and `agenthub` = `LANES_ROOT`) can hide them — Settings → Git → **Worktrees** (`/settings/worktrees`) for every project, and a project's own page (`/settings/projects/<encoded root>`) to override the sources for that project only (`projectHideSources`) — and the project row then says "N hidden" — a click shows them for this visit.
+- **A project's settings page** — Settings → Projects → <repo> shows the repository's root, main branch and worktree count, links each of its workspaces, holds the per-project worktree override above, and offers **Forget all workspaces…**: after one confirm listing them it runs the same `remove` as the row menu for each (preflight, then `POST /api/lanes/:id/remove` with those facts as `expect`) and stops at the first refusal. Forgetting drops AgentHub's records only — nothing on disk is deleted.
 - **No workspaces yet** — the page shows a single banner (`lane-empty`): icon, one line of what a workspace is, the CLI equivalent (`agenthub lanes add --cwd $(pwd)`) and an **Add workspace** affordance. The whole banner IS the button — clicking anywhere on it opens the Add-workspace modal. The banner stays compact on purpose: the run setup form below it is what needs the height.
 - **Reordering** — drag a row onto another within its project, or press **Alt+↑/↓** with a row focused. The order is a **per-viewer preference**, not a workspace fact: it persists to `localStorage` (`agenthub.workspace.laneOrder`) and writes nothing server-side — `GET /api/lanes` and `agenthub lanes` keep answering in id order, and the order does not follow you to another browser. A workspace the stored order has never seen lands at the END of its project; a stored id whose workspace is gone is skipped.
 - **Renaming a workspace** — double-click its sidebar row (or Rename in the row menu) to edit in place. **Enter** saves via `PATCH /api/lanes/:id` with `{title}`, **Escape** and clicking away both cancel, and saving an empty name clears the title, which puts the folder name back in its place. Renaming is display-only — a managed workspace's branch name was slugified from its title once, at creation.
@@ -1714,7 +1715,7 @@ agenthub stage <stage> [--evidence "..."]         # Report the current stage
 
 ## Workspaces on any AI tool
 
-A workspace can run any AI coding CLI in the AI Tools catalog (`server/data/ai-tools/*.json`, plus any `*.json` in `DASHBOARD_AI_TOOLS_DIR`, which replaces a built-in file with the same `id` but may not set `launcher`). The **AI Tools** button at the right of the Settings tab bar opens a dialog (also `/settings#ai-tools`) that lists what is installed (found on PATH; **Refresh** re-reads the login shell's PATH first) with an enable switch, **Set default** and **Update** (for every tool whose catalog file names an updater — no version lookup, the updater itself reports "up to date"), and, folded behind a disclosure, what is available to install with a homepage link. The Add-workspace modal shows the chosen tool as one button (the default until changed); clicking it lists every installed, enabled tool as buttons to pick from; `agenthub lanes add --tool <id>` does the same from a terminal. The run form's **Model** picker lists the workspace tool's own models (`GET /api/ai-tools/:id/models`; Claude, Codex, and any catalog tool whose file declares `model: { flag }` — the id is validated and passed as `<flag> <id>`), plus **Custom…**, and starts on the tool's default model when one is set.
+A workspace can run any AI coding CLI in the AI Tools catalog (`server/data/ai-tools/*.json`, plus any `*.json` in `DASHBOARD_AI_TOOLS_DIR`, which replaces a built-in file with the same `id` but may not set `launcher`). Settings → Agents → **AI tools** (`/settings/agents`; the old `/settings#ai-tools` redirects there) lists what is installed (found on PATH; **Refresh** re-reads the login shell's PATH first) with an enable switch, **Set default** and **Update** (for every tool whose catalog file names an updater — no version lookup, the updater itself reports "up to date"), and, folded behind a disclosure, what is available to install with a homepage link. The Add-workspace modal shows the chosen tool as one button (the default until changed); clicking it lists every installed, enabled tool as buttons to pick from; `agenthub lanes add --tool <id>` does the same from a terminal. The run form's **Model** picker lists the workspace tool's own models (`GET /api/ai-tools/:id/models`; Claude, Codex, and any catalog tool whose file declares `model: { flag }` — the id is validated and passed as `<flag> <id>`), plus **Custom…**, and starts on the tool's default model when one is set.
 
 A catalog file: