Route Branch selectors through Working Directory Update

[ScottArbeit]

Route Branch selectors through Working Directory Update

Related to Issue #1025.

Why

Branch ID/name switching is a supported Grace workflow. It must receive the same local-integrity, restart, cancellation, and truthful-result behavior as exact Reference switching before Issue #835 can complete.

What changed

• Record the approved Branch-selector-to-Reference mapping in the WDU specification and ADR.
• Preserve Branch ID precedence when both ID and name are supplied.
• Resolve the selected Branch once and bind its exact latest nonempty Reference.
• Validate repository, Branch, Reference, and target-root identities before mutation.
• Route no-Save and Save-enabled Branch selectors through the existing exact-Reference WDU paths.
• Preserve explicit Reference, hash, unsupported-selector, output, and command-surface behavior.

No WDU contracts or implementation, persistence, project shape, Server, SDK, OpenAPI, or generated artifacts changed.

Validation

• Issue WDU prerequisite: Route Branch-ID/name switching through Working Directory Update #1025 focused tests: 8/8
• Complete BranchCommandTests: 60/60
• Branch CLI parsing tests: 49/49
• Release build: 0 warnings, 0 errors
• WDU lifecycle packet: 53/53
• WDU raw projection: 12/12
• WDU raw export: 6/6
• WDU contract suite: 110/110
• Built help/schema/examples: 31/131/79, all passing
• Fantomas, MarkdownLint, and git diff --check: clean

GitHub Validate, Shape Review, and R1 are required on the current PR head before merge.

Residual risk

There is no live-server Branch-selector integration test. The built action boundary covers public routing and selector identity, while existing WDU tests cover the reused mutation and completion path.

Delivery

• Base: epic/835-working-directory-update
• Candidate head: 433dac8fa67aa30091681e9e501ee2f6c1834730
• Candidate tree: 560e6b649466bfbcd1f9c601788f88d304cd8cda
• Docs impact: WDU specification and ADR updated
• Skipped: local Fast/Full, because focused tests plus required GitHub Validate cover this bounded caller-routing change

[ScottArbeit]

Landing evidence

Pinned approved head: 1857f2a4ac5c7b7feab4e6cd7476317a81c87a00

• Shape Review completed with zero owner questions at the pre-repair head. The accepted repair changed only comparison behavior and tests, with no declaration or data-relationship change, so the report remains current under the shape-neutral repair rule.
• R1 found one Product V1 compatibility regression: the new post-resolution Branch-name check was case-sensitive while the server resolves names case-insensitively.
• The repair now uses ordinal case-insensitive comparison, accepts feature for stored Feature, and still rejects a genuinely different name.
• R2 verdict: VERIFIED.
• Repaired-head focused tests: Issue WDU prerequisite: Route Branch-ID/name switching through Working Directory Update #1025 10/10; complete Branch command fixture 62/62; Release build clean; formatting and git diff --check clean.
• Current-head GitHub Validate: passed, run 32910258112.
• Accepted risk: no live-server Branch-selector integration test; built-action routing plus existing Reference/WDU tests cover the bounded change.

Owner approved PR #1027 at the pinned repaired head. The candidate is ready to merge to epic/835-working-directory-update.