Remove DedicatedMachine; re-home PendingQuestion to the daemon Machine

[pulzzejason]

Problem

The project-scoped DedicatedMachine machine-pairing system is superseded by the account-scoped Machine daemon. With the account-level Machines page now live (#143, PR #499), the legacy project machines page should be removed — but the PendingQuestion (machine ask/answer) capability is preserved by re-homing it onto the new Machine.

Task: #144 (remove-legacy-dedicatedmachine-project-machines-implementati)

Confirmed decisions

• Remove the DedicatedMachine model + enum + Project.dedicatedMachines back-relation, the project-scoped machines list/CRUD routes, companion/pair, the project machines page + src/components/machines/*.
• Keep + re-home PendingQuestion: repoint its FK from DedicatedMachine → the account-scoped Machine; add account-scoped ping/questions/answer routes under /api/v1/me/machines/[id]/.... (The PM-bridge Sessions question flow is untouched.)
• Data loss accepted (days-old superseded feature; DROP migration may drop rows).
• Repoint dangling links to the account-level /machines page (feat: peter-current-working-branch-2 #143). Note NoMachineBanner already points there.

Acceptance criteria

• DedicatedMachine model + DedicatedMachineStatus enum + Project.dedicatedMachines removed; prisma validate + typecheck pass.
• PendingQuestion preserved, machineId now → Machine (new Machine.pendingQuestions); PendingQuestionStatus kept.
• Machine ping/question/answer live under account-scoped /api/v1/me/machines/[id]/...; old project-scoped equivalents gone.
• Project machines list/CRUD routes, companion/pair, project machines page, and src/components/machines/* deleted.
• No dangling references; npm run build succeeds.
• New daemon (/api/v1/me/machines, docker/agent/*), /agent rooms, and the feat: peter-current-working-branch-2 #143 page remain green; CompanionToken/ProjectSyncToken.machineFingerprint untouched.
• Once re-homed, the feat: peter-current-working-branch-2 #143 drill-in "Pending questions" section populates from real data (closes that dependency).

Notes for the implementer

• The codebase shifted since spec: T113 (PR feat(machines): agent machines + gh/Claude login status per project (T113, stacked on #445) #447) merged more into the legacy project machines page, and feat: peter-current-working-branch-2 #143 shipped the account-level replacement. Re-grep against current main — the removal targets (…/machines/page.tsx, machines-page-client.tsx, components/machines/*) now include T113's additions and get removed wholesale.

Security

Account-scoped question routes must use authorizeDaemonOrSession + userId (test non-owner rejection); zod-validate question/answer bodies. DROP migration destroys dedicated_machines + pending_questions rows (accepted).

Rollback

Revert PR; re-run the original migration to recreate the (empty) tables.

Full spec: .tasks/.data/tasks/remove-legacy-dedicatedmachine-project-machines-implementati.md