Add hazzel tool card

[mukundzha]

Adds data/tools/hazzel.yaml and regenerates the README via scripts/generate_readme.py (not hand-edited).

Card shape

• category: [agent, vcs] — it's a coding agent with real git integration (/commit, /review, /diff, /status, /log, /undo)
• lang: python, binary: hazzel, detected via --version and a local .hazzel/ dir
• risk.level: high, destructive: true — it can run arbitrary approved shell, including rm, so confirmation is required for every write, command, and commit

Guardrails listed

• Every mutating tool call blocks on a diff preview
• Pre-write snapshots under ~/.config/hazzel/undo/, so /undo reverts the agent's hunks and keeps edits made afterwards
• Commands sandboxed to the project root; git reset --hard/git clean blocked, raw git commit redirected to /commit
• Ask-once approvals settle a y/N for the turn
• /allow opts out of the gate entirely, which the card calls out explicitly

Verification

python scripts/lint_registry.py     # Validated 461 tool cards.
python scripts/generate_readme.py   # deterministic across two runs

Counters updated by the generator: tools 460 → 461, high-risk 144 → 145, agent category 106 → 107.