#87: Pin immutable Research Execution Profiles

[justsml]

Split from the Wayfinder mega PR #137.

Refs #87

Scope

• Resolve, persist, and propagate immutable model, capability, skill, target, network, budget, UI, and policy selections.

Review notes

This PR is intentionally ticket-scoped. It does not close the referenced issue unless the issue is already complete; CI provides the final integration check.

[justsml]

Council of Dans review: repair/defer. Highest-priority gate: Restack off the closed #156 implementation and rebuild on native bounded Workspace search; then prove requested/effective profile propagation without no-op controller cost. Feature flags are not a substitute for authority, evidence-integrity, or durability fixes; use typed modes only where they provide a real rollout boundary.

[justsml]

Council hard-stop update after 3 review-and-repair loops:

Pushed 34abcc78e and a5c232a46. The PR is now draft because central immutability blockers remain.

Resolved:

• exact run/profile lookup for background work;
• full authority-free profile projection;
• full model URI/provider-option gateway;
• pinned skill bodies and server-owned handoff profile;
• public drain route no longer accepts grants;
• persisted-first resume and expanded profile propagation;
• 47 focused integration checks, typecheck, and formatting pass.

Remaining P1 blockers:

1. production target config still prefers the fresh nested thread workspace over the pinned profile;
2. scheduler claims are project/thread-wide and can claim another run/profile task before rejecting it;
3. the exported background boundary still accepts/persists caller approval grants;
4. remote stages lose the pinned compute target ID;
5. arbitrary nonexistent model IDs on supported providers still publish.

P2: enforce run/profile custody for parent handoffs and add a production Controller option propagation test.

Per the three-loop stop rule, this PR is parked and remains open as a draft.