docs: AI runs in the workspace container in wave one (ADRs 0009, 0012)

[wstein]

Docs lane #66: AI agents run inside the workspace container in wave one. Adds ADR 0009 (amends ADR 0006: agent interop via an in-container session interface), ADR 0012 (persistent console), updates product.md and architecture.md, and reconciles Feature 001 (spec.md, tasks.md, data-model.md) with the persistent console.

Owner-directed scope: H7:a, H9:a (AI in container, session interface), H22:a (amend specs/001 spec.md for the persistent console), H26:a (also tasks.md and data-model.md), H16:b (session interface as its own contract, #71), H31:a (rebind the protected feature baseline in tests/test_single_task_scope.py: BASELINE 95b5bed -> e5c9f15, specs/001-workspace-lifecycle tree 0fda80d6 -> bae1fd2c; one separate commit, ee0a66e). The constitution is NOT amended here (tracked in #75). plan.md:61-62 is intentionally unedited (outside H26:a).

Draft because: make check is not yet green on this head. Evidence so far, exact head ee0a66e:

• Opus (claude-opus-5-5) protected-path review CLEAR; focused ProtectedFeatureIdentityTests pass. No full make check result yet; the serial run is in progress.
• The earlier head e5c9f15 failed only that protected-identity test (exit 2, 818 tests, 1 failure), which ee0a66e addresses.
• Will be marked ready only after a green make check on the exact head.

Stack: main <- this PR <- #67 (#74) <- #68. Rebase-merge in that order.

Non-blocking nits go to speckit-plan input: ADR 0012 cites plan.md by line numbers; console-session state model is follow-up.

Refs #66 #71 #75

[wstein]

Closing as superseded: the #66 content is already on main via rebase-merge (5ca3765..9148480: ADRs 0009 and 0012, specs/001 reconciliation, protected baseline rebind). This branch's tree is identical to main and its head is a merge commit (aace10e), which the linear-history rule excludes. Owner decision H33:a, 2026-10-14.