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/slack/SKILL.md

@@ -0,0 +1,133 @@
+---
+name: slack
+description: >-
+  Send Slack messages, view channel history, search conversations, find users, and manage team communication. Use when the user wants to interact with Slack.
+license: MIT
+compatibility: Designed for Rowboat desktop app
+metadata:
+  version: "1.0.0"
+  title: "Slack Integration"
+  author: rowboatlabs
+  tags: "slack, messaging, communication"
+---
+
+# Slack Integration Skill (agent-slack CLI)
+
+You interact with Slack by running **agent-slack** commands through \`executeCommand\`.
+
+---
+
+## 1. Check Connection
+
+Before any Slack operation, read \`~/.rowboat/config/slack.json\`. If \`enabled\` is \`false\` or the \`workspaces\` array is empty, simply tell the user: "Slack is not enabled. You can enable it in the Connectors settings." Do not attempt any agent-slack commands.
+
+If enabled, use the workspace URLs from the config for all commands.
+
+---
+
+## 2. Core Commands
+
+### Messages
+
+| Action | Command |
+|--------|---------|
+| List recent messages | \`agent-slack message list "#channel-name" --limit 25\` |
+| List thread replies | \`agent-slack message list "#channel" --thread-ts 1234567890.123456\` |
+| Get a single message | \`agent-slack message get "https://team.slack.com/archives/C.../p..."\` |
+| Send a message | \`agent-slack message send "#channel-name" "Hello team!"\` |
+| Reply in thread | \`agent-slack message send "#channel-name" "Reply text" --thread-ts 1234567890.123456\` |
+| Edit a message | \`agent-slack message edit "#channel-name" --ts 1234567890.123456 "Updated text"\` |
+| Delete a message | \`agent-slack message delete "#channel-name" --ts 1234567890.123456\` |
+
+**Targets** can be:
+- A full Slack URL: \`https://team.slack.com/archives/C01234567/p1234567890123456\`
+- A channel name: \`"#general"\` or \`"general"\`
+- A channel ID: \`C01234567\`
+
+### Reactions
+
+\`\`\`
+agent-slack message react add "<target>" <emoji> --ts <ts>
+agent-slack message react remove "<target>" <emoji> --ts <ts>
+\`\`\`
+
+### Search
+
+\`\`\`
+agent-slack search messages "query text" --limit 20
+agent-slack search messages "query" --channel "#channel-name" --user "@username"
+agent-slack search messages "query" --after 2025-01-01 --before 2025-02-01
+agent-slack search files "query" --limit 10
+\`\`\`
+
+### Channels
+
+\`\`\`
+agent-slack channel new --name "project-x" --workspace https://team.slack.com
+agent-slack channel new --name "secret-project" --private
+agent-slack channel invite --channel "#project-x" --users "@alice,@bob"
+\`\`\`
+
+### Users
+
+\`\`\`
+agent-slack user list --limit 200
+agent-slack user get "@username"
+agent-slack user get U01234567
+\`\`\`
+
+### Canvases
+
+\`\`\`
+agent-slack canvas get "https://team.slack.com/docs/F01234567"
+agent-slack canvas get F01234567 --workspace https://team.slack.com
+\`\`\`
+
+---
+
+## 3. Multi-Workspace
+
+**Important:** The user has chosen which workspaces to use. Before your first Slack operation, read \`~/.rowboat/config/slack.json\` to see the selected workspaces. Only interact with workspaces listed in that config — ignore any other authenticated workspaces.
+
+If the selected workspace list contains multiple entries, use \`--workspace <url>\` to disambiguate:
+
+\`\`\`
+agent-slack message list "#general" --workspace https://team.slack.com
+\`\`\`
+
+If only one workspace is selected, always use \`--workspace\` with its URL to avoid ambiguity with other authenticated workspaces.
+
+---
+
+## 4. Token Budget Control
+
+Use \`--limit\` to control how many messages/results are returned. Use \`--max-body-chars\` or \`--max-content-chars\` to truncate long message bodies:
+
+\`\`\`
+agent-slack message list "#channel" --limit 10
+agent-slack search messages "query" --limit 5 --max-content-chars 2000
+\`\`\`
+
+---
+
+## 5. Discovering More Commands
+
+For any command you're unsure about:
+
+\`\`\`
+agent-slack --help
+agent-slack message --help
+agent-slack search --help
+agent-slack channel --help
+\`\`\`
+
+---
+
+## Best Practices
+
+- **Always show drafts before sending** — Never send Slack messages without user confirmation
+- **Summarize, don't dump** — When showing channel history, summarize the key points rather than pasting everything
+- **Prefer Slack URLs** — When referring to messages, use Slack URLs over raw channel names when available
+- **Use --limit** — Always set reasonable limits to keep output concise and token-efficient
+- **Resolve user IDs** — Messages contain raw user IDs like \`U078AHJP341\`. Resolve them to real names before presenting to the user. Batch all lookups into a single \`executeCommand\` call using \`;\` separators, e.g. \`agent-slack user get U078AHJP341 --workspace ... ; agent-slack user get U090UEZCEQ0 --workspace ...\`
+- **Cross-reference with knowledge base** — Check if mentioned people have notes in the knowledge base