Bug: analysis_tools.py and graph.py — 7 MCP tools crash on valid input (v2.3.2)

[ice5631024721]

Issue Labels

bug

Issue Body

## Environment

- **code-review-graph version:** 2.3.2
- **Python:** 3.12
- **Platform:** macOS (Darwin)

---

## Bug 1: `analysis_tools.py` — `repo_root` type mismatch

### Problem

All 5 functions in `tools/analysis_tools.py` call `_validate_repo_root(repo_root)` directly, passing a bare `str`. But `_validate_repo_root` in `tools/_common.py:61` expects a `Path` object:

```python
# _common.py:68
def _validate_repo_root(path: Path) -> Path:
    resolved = path.resolve()   # ← AttributeError on str

Error: AttributeError: 'str' object has no attribute 'resolve'

Affected MCP tools: get_hub_nodes_tool, get_bridge_nodes_tool, get_knowledge_gaps_tool, get_surprising_connections_tool, get_suggested_questions_tool

Why other tools work

All other modules call _get_store(repo_root) which internally wraps with Path(). Only analysis_tools.py bypasses this.

Fix (5 lines)

In tools/analysis_tools.py, replace all instances of:

root = _validate_repo_root(repo_root)
store = _get_store(str(root))

with:

store, root = _get_store(repo_root)

---

Bug 2: graph.py — get_communities_list returns incomplete sqlite3.Row

Problem

# graph.py:1091
"SELECT id, name FROM communities"

But analysis.py:148 does c.get("size", 0) — two problems:

1. Missing size column in the SELECT
2. sqlite3.Row has no .get() method (crashes with AttributeError: 'sqlite3.Row' object has no attribute 'get')

Affected: get_knowledge_gaps_tool, get_suggested_questions_tool

Fix

def get_communities_list(self) -> list[dict]:
    try:
        return [
            dict(r)
            for r in self._conn.execute(
                "SELECT id, name, size, level, cohesion, dominant_language "
                "FROM communities"
            ).fetchall()
        ]
    except sqlite3.OperationalError as exc:
        logger.debug("Communities list unavailable: %s", exc)
        return []

---

Combined Impact

7 out of ~20 MCP tools are completely non-functional in v2.3.2.

Both fixes are minimal, non-breaking, and follow the existing code patterns.