fix(server): empty Claude homePath shares continuation with ~/.claude

[cestercian]

Summary

Empty CLAUDE_CONFIG_DIR / homePath used to resolve to bare $HOME, so the default Claude instance and an explicit ~/.claude got different continuation group keys even though Claude stores sessions under ~/.claude either way.

resolveClaudeHomePath now matches the CLI: configured homePath → inherited CLAUDE_CONFIG_DIR → ~/.claude. Empty, ~/.claude, and the expanded absolute path share the same claude:home:… key. ClaudeDriver passes the merged instance env into continuation and capabilities keys.

Fixes #12616

Test plan

• vp test run apps/server/src/provider/Drivers/ClaudeHome.test.ts — 5 passed
• Switch mid-thread between empty and ~/.claude instances once authenticated

Summary by CodeRabbit

• Bug Fixes
  • Claude configuration now respects an inherited CLAUDE_CONFIG_DIR when no explicit configuration directory is provided.
  • Explicit configuration paths take precedence over inherited environment settings.
  • Empty configuration values no longer unexpectedly fall back to the system home directory.
  • Claude continuation handling and capability caching now remain correctly separated when instances use different environment settings.

[macroscopeapp]

Approvability

Verdict: Not approved

Macroscope's review found this PR not approvable — The PR changes the effective Claude config-directory default for unset homePath values and updates continuation/cache identity to follow that new default. Although the implementation is focused and tested, changing a product default warrants human review.

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[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository: pingdotgg/t3code/.coderabbit.yaml

Review profile: CHILL

Plan: Advanced

Run ID: d0fa6ec7-fb0c-489d-9b1c-fe6342b0aa39

📥 Commits

Reviewing files that changed from the base of the PR and between 8dd0247 and 374ed6f.

📒 Files selected for processing (3)

• apps/server/src/provider/Drivers/ClaudeDriver.ts
• apps/server/src/provider/Drivers/ClaudeHome.test.ts
• apps/server/src/provider/Drivers/ClaudeHome.ts

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📝 Walkthrough

Walkthrough

Claude home resolution now uses configured or inherited CLAUDE_CONFIG_DIR values before the default ~/.claude path. Continuation and capabilities cache keys receive the merged process environment. Tests cover equivalent paths and precedence rules.

Changes

Claude home and key handling

Layer / File(s)	Summary
Environment-aware home and key generation apps/server/src/provider/Drivers/ClaudeHome.ts, apps/server/src/provider/Drivers/ClaudeHome.test.ts	Home resolution prioritizes configured paths, inherited CLAUDE_CONFIG_DIR, and then ~/.claude. Continuation and capabilities cache keys use the resolved path. Tests cover equivalent default paths and explicit-path precedence.
Driver environment propagation apps/server/src/provider/Drivers/ClaudeDriver.ts	The driver passes the merged process environment to continuation-group and capabilities-cache key builders.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix · Severity of issue fixed: Low

Suggested reviewers: t3dotgg

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly identifies the main fix: empty Claude homePath now shares a continuation key with ~/.claude.
Description check	✅ Passed	The description explains what changed, why the change is needed, and how it was tested. It does not use the template headings exactly and does not include the full checklist, but it provides the requi…
Linked Issues check	✅ Passed	The PR satisfies #12616. resolveClaudeHomePath maps empty homePath to ~/.claude, expands explicit ~/.claude, and uses inherited CLAUDE_CONFIG_DIR when applicable. `makeClaudeContinuationGrou…
Out of Scope Changes check	✅ Passed	The changes stay within #12616. The capabilities-cache key uses the same resolved Claude home, and ClaudeDriver passes the merged environment so per-instance resolution remains consistent. The test …
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 3…

✨ Finishing Touches

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[juliusmarminge]

/recheck-vouch