Repair issue command boundaries, recursive project views and Workspace obligations

[briansrls]

Concurrent stale issue commands could fork history, retries could create another operation, and reverse blockers were being used as project ownership. This change adds snapshot-bound revision CAS and atomic operation receipts, uses one URL-encoded form contract, and separates recursive nesting from scheduling dependencies across presentation and worker consumers.

The shell → DAG batch is the first authored membership migration. Clicking a task focuses that project, shows the recent three completed items and upcoming work in dependency order, and expands earlier work with “…”. Undo restores the view. Assignment comes from the committed state, typed ticket fields survive rendering, and fleet placement leaves Google's interface model.

Cut 4.1 also models the five Workspace administration obligations with bounded readback. External directory sharing has a documented Policy API read; mutation remains manual. No Google settings or credentials were changed.

Review order, commit boundaries, known gaps, reproduction commands and receipts: review index.

Validation: actual carrier CAS/race/replay, native browser form decoding, emitted assignment retries and styled project-focus controls pass. Page: 83 pass, one pre-existing brief-budget failure reproduced on the untouched base. Presentation: 57 pass; alignment 42; continuation 22; submission 34; event state 19; Workspace 5. Additional focused results are in the index.

This remains a draft: the full serve witness closure exceeded the unchanged 6 GiB limit, and the base also fails rustfmt on an untouched Rust file. The hook's documented --no-verify override was used only to publish the draft. No merge or deployment; auth, compiler and fleet configuration remain unchanged. This targets the PR #12387 branch and does not depend on or alter held PR #12465.