feat: add marketplace skills as local project skills

Move skill definitions from the nanoclaw-skills marketplace plugin
into .claude/skills/ so they're available as unprefixed slash commands
(e.g. /add-whatsapp instead of /nanoclaw-skills:add-whatsapp).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.claude/skills/add-compact/SKILL.md

@@ -0,0 +1,135 @@
+---
+name: add-compact
+description: Add /compact command for manual context compaction. Solves context rot in long sessions by forwarding the SDK's built-in /compact slash command. Main-group or trusted sender only.
+---
+
+# Add /compact Command
+
+Adds a `/compact` session command that compacts conversation history to fight context rot in long-running sessions. Uses the Claude Agent SDK's built-in `/compact` slash command — no synthetic system prompts.
+
+**Session contract:** `/compact` keeps the same logical session alive. The SDK returns a new session ID after compaction (via the `init` system message), which the agent-runner forwards to the orchestrator as `newSessionId`. No destructive reset occurs — the agent retains summarized context.
+
+## Phase 1: Pre-flight
+
+Check if `src/session-commands.ts` exists:
+
+```bash
+test -f src/session-commands.ts && echo "Already applied" || echo "Not applied"
+```
+
+If already applied, skip to Phase 3 (Verify).
+
+## Phase 2: Apply Code Changes
+
+Merge the skill branch:
+
+```bash
+git fetch upstream skill/compact
+git merge upstream/skill/compact
+```
+
+> **Note:** `upstream` is the remote pointing to `qwibitai/nanoclaw`. If using a different remote name, substitute accordingly.
+
+This adds:
+- `src/session-commands.ts` (extract and authorize session commands)
+- `src/session-commands.test.ts` (unit tests for command parsing and auth)
+- Session command interception in `src/index.ts` (both `processGroupMessages` and `startMessageLoop`)
+- Slash command handling in `container/agent-runner/src/index.ts`
+
+### Validate
+
+```bash
+npm test
+npm run build
+```
+
+### Rebuild container
+
+```bash
+./container/build.sh
+```
+
+### Restart service
+
+```bash
+launchctl kickstart -k gui/$(id -u)/com.nanoclaw  # macOS
+# Linux: systemctl --user restart nanoclaw
+```
+
+## Phase 3: Verify
+
+### Integration Test
+
+1. Start NanoClaw in dev mode: `npm run dev`
+2. From the **main group** (self-chat), send exactly: `/compact`
+3. Verify:
+   - The agent acknowledges compaction (e.g., "Conversation compacted.")
+   - The session continues — send a follow-up message and verify the agent responds coherently
+   - A conversation archive is written to `groups/{folder}/conversations/` (by the PreCompact hook)
+   - Container logs show `Compact boundary observed` (confirms SDK actually compacted)
+   - If `compact_boundary` was NOT observed, the response says "compact_boundary was not observed"
+4. From a **non-main group** as a non-admin user, send: `@<assistant> /compact`
+5. Verify:
+   - The bot responds with "Session commands require admin access."
+   - No compaction occurs, no container is spawned for the command
+6. From a **non-main group** as the admin (device owner / `is_from_me`), send: `@<assistant> /compact`
+7. Verify:
+   - Compaction proceeds normally (same behavior as main group)
+8. While an **active container** is running for the main group, send `/compact`
+9. Verify:
+   - The active container is signaled to close (authorized senders only — untrusted senders cannot kill in-flight work)
+   - Compaction proceeds via a new container once the active one exits
+   - The command is not dropped (no cursor race)
+10. Send a normal message, then `/compact`, then another normal message in quick succession (same polling batch):
+11. Verify:
+    - Pre-compact messages are sent to the agent first (check container logs for two `runAgent` calls)
+    - Compaction proceeds after pre-compact messages are processed
+    - Messages **after** `/compact` in the batch are preserved (cursor advances to `/compact`'s timestamp only) and processed on the next poll cycle
+12. From a **non-main group** as a non-admin user, send `@<assistant> /compact`:
+13. Verify:
+    - Denial message is sent ("Session commands require admin access.")
+    - The `/compact` is consumed (cursor advanced) — it does NOT replay on future polls
+    - Other messages in the same batch are also consumed (cursor is a high-water mark — this is an accepted tradeoff for the narrow edge case of denied `/compact` + other messages in the same polling interval)
+    - No container is killed or interrupted
+14. From a **non-main group** (with `requiresTrigger` enabled) as a non-admin user, send bare `/compact` (no trigger prefix):
+15. Verify:
+    - No denial message is sent (trigger policy prevents untrusted bot responses)
+    - The `/compact` is consumed silently
+    - Note: in groups where `requiresTrigger` is `false`, a denial message IS sent because the sender is considered reachable
+16. After compaction, verify **no auto-compaction** behavior — only manual `/compact` triggers it
+
+### Validation on Fresh Clone
+
+```bash
+git clone <your-fork> /tmp/nanoclaw-test
+cd /tmp/nanoclaw-test
+claude  # then run /add-compact
+npm run build
+npm test
+./container/build.sh
+# Manual: send /compact from main group, verify compaction + continuation
+# Manual: send @<assistant> /compact from non-main as non-admin, verify denial
+# Manual: send @<assistant> /compact from non-main as admin, verify allowed
+# Manual: verify no auto-compaction behavior
+```
+
+## Security Constraints
+
+- **Main-group or trusted/admin sender only.** The main group is the user's private self-chat and is trusted (see `docs/SECURITY.md`). Non-main groups are untrusted — a careless or malicious user could wipe the agent's short-term memory. However, the device owner (`is_from_me`) is always trusted and can compact from any group.
+- **No auto-compaction.** This skill implements manual compaction only. Automatic threshold-based compaction is a separate concern and should be a separate skill.
+- **No config file.** NanoClaw's philosophy is customization through code changes, not configuration sprawl.
+- **Transcript archived before compaction.** The existing `PreCompact` hook in the agent-runner archives the full transcript to `conversations/` before the SDK compacts it.
+- **Session continues after compaction.** This is not a destructive reset. The conversation continues with summarized context.
+
+## What This Does NOT Do
+
+- No automatic compaction threshold (add separately if desired)
+- No `/clear` command (separate skill, separate semantics — `/clear` is a destructive reset)
+- No cross-group compaction (each group's session is isolated)
+- No changes to the container image, Dockerfile, or build script
+
+## Troubleshooting
+
+- **"Session commands require admin access"**: Only the device owner (`is_from_me`) or main-group senders can use `/compact`. Other users are denied.
+- **No compact_boundary in logs**: The SDK may not emit this event in all versions. Check the agent-runner logs for the warning message. Compaction may still have succeeded.
+- **Pre-compact failure**: If messages before `/compact` fail to process, the error message says "Failed to process messages before /compact." The cursor advances past sent output to prevent duplicates; `/compact` remains pending for the next attempt.