feat(ai-autopilot): bootstrap orchestrator core — scope -> architect -> build -> full-fledged loop (#122)

[suleimansh]

Child of #116 (bootstrap). The spine.

Sequences autopilot's existing primitives into one flow, taking a user from nothing to a running, production-grade app:

scope  →  architect  →  build  →  full-fledged loop

• Scope — the one and only interrogation (prototype vs full + intent).
• Architect — picks the stack (Vike + universal-orm), narrates it, and records the key choices to the decisions ledger (Decisions bookkeeping — stop the AI re-pitching rejected ideas #112). No permission asked.
• Build — runs the Supervisor over the stack personas (ai-autopilot: personas + prompts library (stack-aware knowledge) #98) inside a runner (ai-autopilot: LocalRunner — first real runner adapter (host fs + child processes) #106), forwarding its events as narration over the generic surface stream (Generalize the surface stream to be event-type generic #120); the caller can interrupt via AbortSignal.
• Full-fledged loop — fires the change events into the loop ("The loop" — event-triggered prompt chains (major change → review/quality/security; UI flow → QA/UX) #113) and repeats the production-grade checklist (Production-grade checklist prompt + { blockers } verdict convention #121) with fresh context until its { blockers } verdict is empty or a maxPasses budget stops it. Prototype scope skips it.

Bootstrap owns the control flow (loop, gate, interrupt) over four injectable steps, so it runs offline against stubs + FakeRunner. Default step builders wire those steps onto the real primitives:

• agentArchitect — an ai-sdk agent + Output.object, with the decisions briefing prepended so it does not re-pitch a rejected idea.
• supervisorBuild — the Supervisor over a planner + persona workers.
• loopChecklist / loopImprove — the Loop (checklist verdict + firing the review/QA chains).

Tests: orchestration with stubs (happy path, loop-until-clean, stop-at-maxPasses, prototype-skips-loop, abort, observer isolation, construction guards), each default step against real primitives, and a full end-to-end run wiring Bootstrap + all four default steps + AiFake offline. Full suite 158 green.

Stacked on #120 and #121 — base is the #121 branch so this diff is bootstrap-only; it retargets to main once they merge. Merge order: #125 → #126 → this.

Closes #122.