Skills engine v0.1 + multi-channel infrastructure (#307)

* refactor: multi-channel infrastructure with explicit channel/is_group tracking

- Add channels[] array and findChannel() routing in index.ts, replacing
  hardcoded whatsapp.* calls with channel-agnostic callbacks
- Add channel TEXT and is_group INTEGER columns to chats table with
  COALESCE upsert to protect existing values from null overwrites
- is_group defaults to 0 (safe: unknown chats excluded from groups)
- WhatsApp passes explicit channel='whatsapp' and isGroup to onChatMetadata
- getAvailableGroups filters on is_group instead of JID pattern matching
- findChannel logs warnings instead of silently dropping unroutable JIDs
- Migration backfills channel/is_group from JID patterns for existing DBs

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

* feat: skills engine v0.1 — deterministic skill packages with rerere resolution

Three-way merge engine for applying skill packages on top of a core
codebase. Skills declare which files they add/modify, and the engine
uses git merge-file for conflict detection with git rerere for
automatic resolution of previously-seen conflicts.

Key components:
- apply: three-way merge with backup/rollback safety net
- replay: clean-slate replay for uninstall and rebase
- update: core version updates with deletion detection
- rebase: bake applied skills into base (one-way)
- manifest: validation with path traversal protection
- resolution-cache: pre-computed rerere resolutions
- structured: npm deps, env vars, docker-compose merging
- CI: per-skill test matrix with conflict detection

151 unit tests covering merge, rerere, backup, replay, uninstall,
update, rebase, structured ops, and edge cases.

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

* feat: add Discord and Telegram skill packages

Skill packages for adding Discord and Telegram channels to NanoClaw.
Each package includes:
- Channel implementation (add/src/channels/)
- Three-way merge targets for index.ts, config.ts, routing.test.ts
- Intent docs explaining merge invariants
- Standalone integration tests
- manifest.yaml with dependency/conflict declarations

Applied via: npx tsx scripts/apply-skill.ts .claude/skills/add-discord
These are inert until applied — no runtime impact.

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

* remove unused docs (skills-system-status, implementation-guide)

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

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

.claude/skills/add-discord/tests/discord.test.ts

@@ -0,0 +1,133 @@
+import { describe, expect, it } from 'vitest';
+import fs from 'fs';
+import path from 'path';
+
+describe('discord skill package', () => {
+  const skillDir = path.resolve(__dirname, '..');
+
+  it('has a valid manifest', () => {
+    const manifestPath = path.join(skillDir, 'manifest.yaml');
+    expect(fs.existsSync(manifestPath)).toBe(true);
+
+    const content = fs.readFileSync(manifestPath, 'utf-8');
+    expect(content).toContain('skill: discord');
+    expect(content).toContain('version: 1.0.0');
+    expect(content).toContain('discord.js');
+  });
+
+  it('has all files declared in adds', () => {
+    const addFile = path.join(skillDir, 'add', 'src', 'channels', 'discord.ts');
+    expect(fs.existsSync(addFile)).toBe(true);
+
+    const content = fs.readFileSync(addFile, 'utf-8');
+    expect(content).toContain('class DiscordChannel');
+    expect(content).toContain('implements Channel');
+
+    // Test file for the channel
+    const testFile = path.join(skillDir, 'add', 'src', 'channels', 'discord.test.ts');
+    expect(fs.existsSync(testFile)).toBe(true);
+
+    const testContent = fs.readFileSync(testFile, 'utf-8');
+    expect(testContent).toContain("describe('DiscordChannel'");
+  });
+
+  it('has all files declared in modifies', () => {
+    const indexFile = path.join(skillDir, 'modify', 'src', 'index.ts');
+    const configFile = path.join(skillDir, 'modify', 'src', 'config.ts');
+    const routingTestFile = path.join(skillDir, 'modify', 'src', 'routing.test.ts');
+
+    expect(fs.existsSync(indexFile)).toBe(true);
+    expect(fs.existsSync(configFile)).toBe(true);
+    expect(fs.existsSync(routingTestFile)).toBe(true);
+
+    const indexContent = fs.readFileSync(indexFile, 'utf-8');
+    expect(indexContent).toContain('DiscordChannel');
+    expect(indexContent).toContain('DISCORD_BOT_TOKEN');
+    expect(indexContent).toContain('DISCORD_ONLY');
+    expect(indexContent).toContain('findChannel');
+    expect(indexContent).toContain('channels: Channel[]');
+
+    const configContent = fs.readFileSync(configFile, 'utf-8');
+    expect(configContent).toContain('DISCORD_BOT_TOKEN');
+    expect(configContent).toContain('DISCORD_ONLY');
+  });
+
+  it('has intent files for modified files', () => {
+    expect(fs.existsSync(path.join(skillDir, 'modify', 'src', 'index.ts.intent.md'))).toBe(true);
+    expect(fs.existsSync(path.join(skillDir, 'modify', 'src', 'config.ts.intent.md'))).toBe(true);
+  });
+
+  it('modified index.ts preserves core structure', () => {
+    const content = fs.readFileSync(
+      path.join(skillDir, 'modify', 'src', 'index.ts'),
+      'utf-8',
+    );
+
+    // Core functions still present
+    expect(content).toContain('function loadState()');
+    expect(content).toContain('function saveState()');
+    expect(content).toContain('function registerGroup(');
+    expect(content).toContain('function getAvailableGroups()');
+    expect(content).toContain('function processGroupMessages(');
+    expect(content).toContain('function runAgent(');
+    expect(content).toContain('function startMessageLoop()');
+    expect(content).toContain('function recoverPendingMessages()');
+    expect(content).toContain('function ensureContainerSystemRunning()');
+    expect(content).toContain('async function main()');
+
+    // Test helper preserved
+    expect(content).toContain('_setRegisteredGroups');
+
+    // Direct-run guard preserved
+    expect(content).toContain('isDirectRun');
+  });
+
+  it('modified index.ts includes Discord channel creation', () => {
+    const content = fs.readFileSync(
+      path.join(skillDir, 'modify', 'src', 'index.ts'),
+      'utf-8',
+    );
+
+    // Multi-channel architecture
+    expect(content).toContain('const channels: Channel[] = []');
+    expect(content).toContain('channels.push(whatsapp)');
+    expect(content).toContain('channels.push(discord)');
+
+    // Conditional channel creation
+    expect(content).toContain('if (!DISCORD_ONLY)');
+    expect(content).toContain('if (DISCORD_BOT_TOKEN)');
+
+    // Shutdown disconnects all channels
+    expect(content).toContain('for (const ch of channels) await ch.disconnect()');
+  });
+
+  it('modified config.ts preserves all existing exports', () => {
+    const content = fs.readFileSync(
+      path.join(skillDir, 'modify', 'src', 'config.ts'),
+      'utf-8',
+    );
+
+    // All original exports preserved
+    expect(content).toContain('export const ASSISTANT_NAME');
+    expect(content).toContain('export const POLL_INTERVAL');
+    expect(content).toContain('export const TRIGGER_PATTERN');
+    expect(content).toContain('export const CONTAINER_IMAGE');
+    expect(content).toContain('export const DATA_DIR');
+    expect(content).toContain('export const TIMEZONE');
+
+    // Discord exports added
+    expect(content).toContain('export const DISCORD_BOT_TOKEN');
+    expect(content).toContain('export const DISCORD_ONLY');
+  });
+
+  it('modified routing.test.ts includes Discord JID tests', () => {
+    const content = fs.readFileSync(
+      path.join(skillDir, 'modify', 'src', 'routing.test.ts'),
+      'utf-8',
+    );
+
+    expect(content).toContain("Discord JID: starts with dc:");
+    expect(content).toContain("dc:1234567890123456");
+    expect(content).toContain("dc:");
+  });
+});