fix(coding): don't expose primary worktree path in coding context

[ethernet8023]

Problem

The workspace snapshot emitted to the system prompt for linked git worktrees included the primary tree's absolute path:

- Root: /home/user/project-worktree
- Worktree: linked (primary tree at /home/user/project)

The agent sees two absolute paths and — often gravitating toward the word 'primary' — sometimes runs terminal commands, edits files, or runs git operations against the main tree instead of the worktree it was asked to operate on.

Fix

Drop the primary tree path from the output. The agent still learns it's in a linked worktree (so it knows branches/stashes are shared state), but sees only one absolute path — the one it should operate in.

- Root: /home/user/project-worktree
- Worktree: linked (git state shared with primary tree)

Tests

Added TestProjectFacts.test_worktree_detected_without_primary_path: creates a real linked worktree via git worktree add, confirms the "Worktree: linked" marker is present, and asserts that the primary tree path does NOT appear anywhere in the output.

Also fixed a pre-existing latent bug in the test helper _git_init, which deleted path from env, making git not work. now we pass the binary explicitly.

[github-actions]

🔎 Lint report: hermes-worktree-code vs origin/main

ruff

Total: 0 on HEAD, 0 on base (➖ 0)

🆕 New issues: none

✅ Fixed issues: none

Unchanged: 0 pre-existing issues carried over.

ty (type checker)

Total: 10765 on HEAD, 10764 on base (🆕 +1)

🆕 New issues (1):

Rule	Count
no-matching-overload	1

First entries

tests/agent/test_coding_context.py:24: [no-matching-overload] no-matching-overload: No overload of function `run` matches arguments

✅ Fixed issues: none

Unchanged: 5637 pre-existing issues carried over.

Diagnostics are surfaced as warnings — this check never fails the build.

[tonydwb]

Code Review Summary

Verdict: Approved

Security Fix - Looks Good

• agent/coding_context.py — No longer exposes the absolute path to the primary git tree in worktree contexts. This prevents the model from running commands in the wrong directory.
• Good comment explaining the rationale for the change.
• New test test_worktree_detected_without_primary_path verifies the path is not exposed.

Code Quality

• Clean, minimal change with focused intent.
• No security concerns.

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Reviewed by Hermes Agent