feat(roo): add Patrick-persona custom modes, skills, and mode-specific rules

Add 4 new custom modes with BigMind guidance:
- rules-bigmind/: Introspective Patrick mode (BigMind development)
- rules-homelab/: Tinkerer Patrick mode (TrueNAS, Docker, infra)
- rules-mcp-builder/: Craftsman Patrick mode (pi_mcps MCP servers)
- rules-paisy/: Professional Patrick mode (ADP Germany payroll)

Add reusable skills:
- skills/assessment-first/: structured assessment.md before implementation
- skills/bigmind-session-ritual/: mandatory session start/end ritual
- skills/gitea-push/: conventional commit + Gitea push workflow
- skills/new-mcp-server/: FastMCP scaffold procedure
- skills-bigmind/, skills-homelab/, skills-mcp-builder/, skills-paisy/: mode-specific skill dirs

Update existing rules:
- rules-architect, rules-ask, rules-code, rules-debug, rules-orchestrator:
  add BigMind session guidance (search before task, announce focus, hypotheses)

Add plans/MODES_AND_SKILLS_PLAN.md: full architecture document

.roo/skills-bigmind/bigmind-migration/SKILL.md

@@ -0,0 +1,105 @@
+---
+name: bigmind-migration
+description: Scaffolds a new BigMind database schema migration (v_n to v_{n+1}), including the migration function, SCHEMA_VERSION bump, and test stubs. Use this skill when adding new tables or columns to the BigMind SQLite database.
+---
+
+# BigMind Migration
+
+## When to use
+- Adding a new table to BigMind
+- Adding columns to an existing table
+- Creating a new FTS5 virtual table
+
+## When NOT to use
+- Non-schema changes (just code, no DB structure changes)
+- Dropping or renaming columns (requires extra deprecation care — discuss first)
+
+## Inputs required
+- **Current schema version** — check `SCHEMA_VERSION` in `db.py`
+- **New version** — `current + 1`
+- **Changes** — what tables/columns are being added
+
+## Workflow
+
+### Step 1 — Read current schema
+```bash
+grep -n "SCHEMA_VERSION" ~/.mcp/bigmind/bigmind/db.py
+grep -n "_migrate_v" ~/.mcp/bigmind/bigmind/db.py
+```
+Know what version you're migrating FROM.
+
+### Step 2 — Write migration function in `db.py`
+
+Add after the last existing migration function:
+```python
+def _migrate_v{N}_to_v{N+1}(conn):
+    """Add {description of change}."""
+    cursor = conn.cursor()
+    
+    # Example: new table
+    cursor.execute("""
+        CREATE TABLE IF NOT EXISTS {table_name} (
+            id TEXT PRIMARY KEY,
+            user_id TEXT NOT NULL,
+            created_at TEXT NOT NULL DEFAULT (datetime('now')),
+            -- other columns
+            FOREIGN KEY (user_id) REFERENCES users(id)
+        )
+    """)
+    
+    # Example: FTS5 virtual table
+    cursor.execute("""
+        CREATE VIRTUAL TABLE IF NOT EXISTS {table_name}_fts
+        USING fts5(content, tokenize='porter')
+    """)
+    
+    conn.commit()
+```
+
+### Step 3 — Wire into `init_db()`
+
+In the migration chain inside `init_db()`:
+```python
+SCHEMA_VERSION = {N+1}  # bump this
+
+# In the migration section:
+if current_version < {N+1}:
+    _migrate_v{N}_to_v{N+1}(conn)
+    current_version = {N+1}
+```
+
+### Step 4 — Write tests
+
+In `tests/test_memory_store.py` (or a new test file):
+```python
+class TestMigration_v{N}_to_v{N+1}:
+    def test_fresh_db_has_new_table(self, tmp_path):
+        db_path = tmp_path / "test.db"
+        conn = get_connection(str(db_path))
+        init_db(conn)
+        # Assert new table exists
+        cursor = conn.execute("SELECT name FROM sqlite_master WHERE type='table' AND name='{table_name}'")
+        assert cursor.fetchone() is not None
+
+    def test_existing_db_migrates_cleanly(self, tmp_path):
+        # Create a v{N} db, then run init_db() and check migration ran
+        ...
+```
+
+### Step 5 — Run full test suite
+```bash
+cd ~/.mcp/bigmind
+uv run pytest tests/ -v
+```
+All tests must pass.
+
+### Step 6 — Store migration fact
+```
+memory_store_fact("codebase", "BigMind schema migrated v{N}→v{N+1}: added {description}. Migration function: _migrate_v{N}_to_v{N+1}.")
+```
+
+## Troubleshooting
+- **`IF NOT EXISTS` is your friend:** Always use it so the migration is idempotent
+- **FTS5 table ordering:** Create the base table before the FTS5 virtual table that references it
+- **Migration not running:** Check the `if current_version < X:` guard — verify `current_version` is read correctly from `PRAGMA user_version`
+- **Test DB state:** Use `tmp_path` fixture for isolated test databases — never test against the real `memory.db`