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>

scripts/generate-ci-matrix.ts

@@ -0,0 +1,118 @@
+#!/usr/bin/env npx tsx
+
+import fs from 'fs';
+import path from 'path';
+import { parse } from 'yaml';
+import { SkillManifest } from '../skills-engine/types.js';
+
+export interface MatrixEntry {
+  skills: string[];
+  reason: string;
+}
+
+export interface SkillOverlapInfo {
+  name: string;
+  modifies: string[];
+  npmDependencies: string[];
+}
+
+/**
+ * Extract overlap-relevant info from a parsed manifest.
+ * @param dirName - The skill's directory name (e.g. 'add-discord'), used in matrix
+ *   entries so CI/scripts can locate the skill package on disk.
+ */
+export function extractOverlapInfo(manifest: SkillManifest, dirName: string): SkillOverlapInfo {
+  const npmDeps = manifest.structured?.npm_dependencies
+    ? Object.keys(manifest.structured.npm_dependencies)
+    : [];
+
+  return {
+    name: dirName,
+    modifies: manifest.modifies ?? [],
+    npmDependencies: npmDeps,
+  };
+}
+
+/**
+ * Compute overlap matrix from a list of skill overlap infos.
+ * Two skills overlap if they share any `modifies` entry or both declare
+ * `structured.npm_dependencies` for the same package.
+ */
+export function computeOverlapMatrix(skills: SkillOverlapInfo[]): MatrixEntry[] {
+  const entries: MatrixEntry[] = [];
+
+  for (let i = 0; i < skills.length; i++) {
+    for (let j = i + 1; j < skills.length; j++) {
+      const a = skills[i];
+      const b = skills[j];
+      const reasons: string[] = [];
+
+      // Check shared modifies entries
+      const sharedModifies = a.modifies.filter((m) => b.modifies.includes(m));
+      if (sharedModifies.length > 0) {
+        reasons.push(`shared modifies: ${sharedModifies.join(', ')}`);
+      }
+
+      // Check shared npm_dependencies packages
+      const sharedNpm = a.npmDependencies.filter((pkg) =>
+        b.npmDependencies.includes(pkg),
+      );
+      if (sharedNpm.length > 0) {
+        reasons.push(`shared npm packages: ${sharedNpm.join(', ')}`);
+      }
+
+      if (reasons.length > 0) {
+        entries.push({
+          skills: [a.name, b.name],
+          reason: reasons.join('; '),
+        });
+      }
+    }
+  }
+
+  return entries;
+}
+
+/**
+ * Read all skill manifests from a skills directory (e.g. .claude/skills/).
+ * Each subdirectory should contain a manifest.yaml.
+ * Returns both the parsed manifest and the directory name.
+ */
+export function readAllManifests(skillsDir: string): { manifest: SkillManifest; dirName: string }[] {
+  if (!fs.existsSync(skillsDir)) {
+    return [];
+  }
+
+  const results: { manifest: SkillManifest; dirName: string }[] = [];
+  const entries = fs.readdirSync(skillsDir, { withFileTypes: true });
+
+  for (const entry of entries) {
+    if (!entry.isDirectory()) continue;
+
+    const manifestPath = path.join(skillsDir, entry.name, 'manifest.yaml');
+    if (!fs.existsSync(manifestPath)) continue;
+
+    const content = fs.readFileSync(manifestPath, 'utf-8');
+    const manifest = parse(content) as SkillManifest;
+    results.push({ manifest, dirName: entry.name });
+  }
+
+  return results;
+}
+
+/**
+ * Generate the full CI matrix from a skills directory.
+ */
+export function generateMatrix(skillsDir: string): MatrixEntry[] {
+  const entries = readAllManifests(skillsDir);
+  const overlapInfos = entries.map((e) => extractOverlapInfo(e.manifest, e.dirName));
+  return computeOverlapMatrix(overlapInfos);
+}
+
+// --- Main ---
+if (process.argv[1] && path.resolve(process.argv[1]) === path.resolve(import.meta.url.replace('file://', ''))) {
+  const projectRoot = process.cwd();
+  const skillsDir = path.join(projectRoot, '.claude', 'skills');
+  const matrix = generateMatrix(skillsDir);
+  console.log(JSON.stringify(matrix, null, 2));
+}