Closes the three specific_asks from Jobs's T1 review of the workspace
architecture fix (7829acc..15e3863):
1. docs/architecture/workspace-concurrency.md: decision table
upgraded from a code block to a real Markdown table so it reads
consistently with the failure-modes table lower in the file.
2. docs/architecture/workspace-concurrency.md + resolve-workspace.ts:
added "Sunset coding-role inference" section and a TODO marker on
CODING_ROLE_PATTERN tying the regex to the v52 transition window
(target 2026-05-20). Both documents now name the end-state
explicitly so a future engineer knows why the regex exists and
when it dies.
3. resolve-workspace.ts: enriched the WorkspaceConfigurationError
message to include taskId / agentId / projectId alongside the
existing companyId, so a misconfigured setup points operators at
the offending row instead of just the company.
No behaviour change, no fallback, no mock. typecheck green, 540 unit
tests green, 10 eval tests green.