feat: Implement Git commit hash tracking

[ezyang]

Stack from ghstack (oldest at bottom):

• feat: add click parsing with hello-world flag #252
• back to claude for debugging #250
• feat: replace playground with stdin loop in agno.py #249
• feat: Gemini Agno #248
• -> feat: Implement Git commit hash tracking #247
• feat: use git commit hash as chat ID #246
• feat: use git commit hash instead of static chat id #245

Instead of passing a single static chat id across all conversations, we're going to pass the current Git commit hash. Whenever a command returns, we will query and report what the new current commit hash is in the output. Update the system prompt to ensure that we maintain a current commit hash state and pass it / update it to all tool calls. Do NOT manually update every subtool, instead, there should be unified handling in the codemcp tool main body. Previously you already implemented get_current_commit_hash and you started refactoring codemcp function. By the way, you should refactor so you DON'T have to keep repeating append_commit_hash over and over.

baa2ceb  (Base revision)
dbaf3e4  Modify append_commit_hash to return a tuple with result and commit hash
c0868f7  Add commit_hash parameter to codemcp function
6a082d9  Update expected parameters to include commit_hash
905d1b5  Add commit_hash to provided parameters
51a53b0  Update ReadFile subtool to use the new append_commit_hash return value
f7913d8  Update WriteFile subtool to use the new append_commit_hash return value
00605df  Update EditFile subtool to use the new append_commit_hash return value
9b80e67  Update LS subtool to use the new append_commit_hash return value
caf8419  Update RM subtool to use the append_commit_hash function
81754da  Update RunCommand subtool to use the append_commit_hash function
6457194  Update Grep subtool to use the append_commit_hash function
4556caf  Update Glob subtool to use the append_commit_hash function
9c1cdc6  Update Think subtool to use the append_commit_hash function
e932f5a  Update UserPrompt subtool to use the append_commit_hash function
347a599  Update Chmod subtool to use the append_commit_hash function
f8f0728  Update system prompt to include Git commit hash tracking information
f8b14e0  Snapshot before auto-format
6a64256  Auto-commit format changes
HEAD     Auto-commit lint changes

codemcp-id: 258-feat-implement-git-commit-hash-tracking