fix: route task and label operations to the configured tracker repo (#530)

[fujiwaranosai850]

Closes #530.

Summary

Fixes tracker-targeting drift so DevClaw uses the configured tracker repository instead of ambient checkout inference in task and label operation flows.

Changes

• route to the configured tracker repo
• route label operations to the configured repo
• complete provider targeting across GitHub paths
• add regression coverage for provider targeting and tick-path behavior
• neutralize repo-specific helper test fixtures

Included commits

• fix: route task_create to configured tracker repo (test: add integration test skeleton for task_update tool #95)
• fix: route label operations to configured repo (test: add integration test skeleton for task_update tool #95)
• fix: complete provider targeting across github paths (test: add integration test skeleton for task_update tool #95)
• test: neutralize repo fixture in helper normalization test

Testing

Added regression coverage in:

Notes

This PR is intentionally scoped to the tracker-targeting fix only.
A self-hosting doc change from the original local commit series was intentionally excluded from this upstream PR.

[fujiwaranosai850]

Closing this draft because the branch included an extra cleanup commit and the body was malformed. Replacing with a clean 3-commit issue-95-only draft.