Normalize commit message hooks

[marcus]

Summary

• add a strict commit-msg hook that normalizes safe prefix inconsistencies and rejects non-td trailing parenthetical suffixes
• install both hooks via git-resolved hook paths so worktrees work correctly
• align docs and release automation with the canonical commit format and add regression tests

Verification

• env -u TD_FEATURE_SYNC_AUTOSYNC -u TD_FEATURE_SYNC_CLI -u TD_ENABLE_FEATURE -u TD_DISABLE_FEATURE -u TD_DISABLE_EXPERIMENTAL -u TD_FEATURES_FILE go test ./...
• manual temp repo/worktree hook install verification
• manual commit-msg normalization and rejection repros