Move skills into apps/skills/, drop override + sync layers

Skills now ship with the app under /apps/skills/ (sibling of /apps/x).
Forge bundles the directory into Resources/skills/; main resolves it via
process.resourcesPath in production and a workspace-relative path in dev,
then registers it in the DI container. The runtime reads SKILL.md files
directly from the bundle — no copy to ~/.rowboat/skills/, no GitHub
tarball sync.

Drop the override layer (FSSkillsRepo, SkillOverride, edit/diff UI,
skill-update notification) since skills are now read-only and only ship
with app updates. Resolver simplifies to a single source.

Add a placeholder substitution layer so skills that need live data
(currently `tracks`, with {{TRACK_BLOCK_SCHEMA}}) keep dynamic content
without depending on TS-module evaluation.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/skills/browser-control/SKILL.md

@@ -0,0 +1,113 @@
+---
+name: browser-control
+description: >-
+  Control Rowboat's embedded browser pane — open sites, inspect the live page, switch tabs, and interact with indexed page elements. Use when the user wants to open a website in-app, search the web in the browser pane, click something on a page, fill a form, or interact with a live webpage inside Rowboat.
+license: MIT
+compatibility: Designed for Rowboat desktop app
+metadata:
+  version: "1.0.0"
+  title: Browser Control
+---
+
+# Browser Control Skill
+
+You have access to the **browser-control** tool, which controls Rowboat's embedded browser pane directly.
+
+Use this skill when the user asks you to open a website, browse in-app, search the web in the browser pane, click something on a page, fill a form, or otherwise interact with a live webpage inside Rowboat.
+
+## Core Workflow
+
+1. Start with `browser-control({ action: "open" })` if the browser pane may not already be open.
+2. Use `browser-control({ action: "read-page" })` to inspect the current page.
+3. The tool returns:
+   - `snapshotId`
+   - page `url` and `title`
+   - visible page text
+   - interactable elements with numbered `index` values
+4. Prefer acting on those numbered indices with `click` / `type` / `press`.
+5. After each action, read the returned page snapshot before deciding the next step.
+
+## Actions
+
+### open
+Open the browser pane and ensure an active tab exists.
+
+### get-state
+Return the current browser tabs and active tab id.
+
+### new-tab
+Open a new browser tab.
+
+Parameters:
+- `target` (optional): URL or plain-language search query
+
+### switch-tab
+Switch to a tab by `tabId`.
+
+### close-tab
+Close a tab by `tabId`.
+
+### navigate
+Navigate the active tab.
+
+Parameters:
+- `target`: URL or plain-language search query
+
+Plain-language targets are converted into a search automatically.
+
+### back / forward / reload
+Standard browser navigation controls.
+
+### read-page
+Read the current page and return a compact snapshot.
+
+Parameters:
+- `maxElements` (optional)
+- `maxTextLength` (optional)
+
+### click
+Click an element.
+
+Prefer:
+- `index`: element index from `read-page`
+
+Optional:
+- `snapshotId`: include it when acting on a recent snapshot
+- `selector`: fallback only when no usable index exists
+
+### type
+Type into an input, textarea, or contenteditable element.
+
+Parameters:
+- `text`: text to enter
+- plus the same target fields as `click`
+
+### press
+Send a key press such as `Enter`, `Tab`, `Escape`, or arrow keys.
+
+Parameters:
+- `key`
+- optional target fields if you need to focus a specific element first
+
+### scroll
+Scroll the current page.
+
+Parameters:
+- `direction`: `"up"` or `"down"` (optional; defaults down)
+- `amount`: pixel distance (optional)
+
+### wait
+Wait for the page to settle, useful after async UI changes.
+
+Parameters:
+- `ms`: milliseconds to wait (optional)
+
+## Important Rules
+
+- Prefer `read-page` before interacting.
+- Prefer element `index` over CSS selectors.
+- If the tool says the snapshot is stale, call `read-page` again.
+- After navigation, clicking, typing, pressing, or scrolling, use the returned page snapshot instead of assuming the page state.
+- Use Rowboat's browser for live interaction. Use web search tools for research where a live session is unnecessary.
+- Do not wrap browser URLs or browser pages in ```filepath blocks. Filepath cards are only for real files on disk, not web pages or browser tabs.
+- If you mention a page the browser opened, use plain text for the URL/title instead of trying to create a clickable file card.