feat(agent-teams): add plugin for multi-agent team orchestration

New plugin with 7 presets (review, debug, feature, fullstack, research,
security, migration), 4 specialized agents, 7 slash commands, 6 skills
with reference docs, and Context7 MCP integration for research teams.

plugins/agent-teams/skills/parallel-feature-development/references/file-ownership.md

@@ -0,0 +1,80 @@
+# File Ownership Decision Framework
+
+How to assign file ownership when decomposing features for parallel development.
+
+## Ownership Decision Process
+
+### Step 1: Map All Files
+
+List every file that needs to be created or modified for the feature.
+
+### Step 2: Identify Natural Clusters
+
+Group files by:
+
+- Directory proximity (files in the same directory)
+- Functional relationship (files that import each other)
+- Layer membership (all UI files, all API files)
+
+### Step 3: Assign Clusters to Owners
+
+Each cluster becomes one implementer's ownership boundary:
+
+- No file appears in multiple clusters
+- Each cluster is internally cohesive
+- Cross-cluster dependencies are minimized
+
+### Step 4: Define Interface Points
+
+Where clusters interact, define:
+
+- Shared type definitions (owned by lead or a designated implementer)
+- API contracts (function signatures, request/response shapes)
+- Event contracts (event names and payload shapes)
+
+## Ownership by Project Type
+
+### React/Next.js Frontend
+
+```
+implementer-1: src/components/{feature}/   (UI components)
+implementer-2: src/hooks/{feature}/        (custom hooks, state)
+implementer-3: src/api/{feature}/          (API client, types)
+shared:        src/types/{feature}.ts      (owned by lead)
+```
+
+### Express/Fastify Backend
+
+```
+implementer-1: src/routes/{feature}.ts, src/controllers/{feature}.ts
+implementer-2: src/services/{feature}.ts, src/validators/{feature}.ts
+implementer-3: src/models/{feature}.ts, src/repositories/{feature}.ts
+shared:        src/types/{feature}.ts      (owned by lead)
+```
+
+### Full-Stack (Next.js)
+
+```
+implementer-1: app/{feature}/page.tsx, app/{feature}/components/
+implementer-2: app/api/{feature}/route.ts, lib/{feature}/
+implementer-3: tests/{feature}/
+shared:        types/{feature}.ts          (owned by lead)
+```
+
+### Python Django
+
+```
+implementer-1: {app}/views.py, {app}/urls.py, {app}/forms.py
+implementer-2: {app}/models.py, {app}/serializers.py, {app}/managers.py
+implementer-3: {app}/tests/
+shared:        {app}/types.py              (owned by lead)
+```
+
+## Conflict Resolution
+
+When two implementers need to modify the same file:
+
+1. **Preferred: Split the file** — Extract the shared concern into its own file
+2. **If can't split: Designate one owner** — The other implementer sends change requests
+3. **Last resort: Sequential access** — Implementer A finishes, then implementer B takes over
+4. **Never**: Let both modify the same file simultaneously