Custos builds a triage queue for the contract pile

Adds an /intake triage queue for bulk-uploaded contracts. Each upload is
classified by an LLM and routed to an existing project (counterparty
match) or a new one with a single click.

Schema:
- documents.intake_role / intake_status / intake_counterparty /
  intake_parent_counterparty / intake_lifecycle_hint / intake_confidence /
  intake_analyzed_at.

Backend:
- New lib/intakeAnalysis.ts: maybeAnalyzeIntake() runs one LLM call that
  determines role (buyer/seller/mutual), status (draft/execution/unknown),
  counterparty, parent entity, lifecycle position (original/amendment/
  renewal/addendum/sow/order_form/etc.), and self-reported confidence.
- Hooked into POST /single-documents and POST /projects/:id/documents,
  fire-and-forget alongside contract-fact extraction.
- GET /single-documents/intake returns pending docs + the user's projects
  for client-side counterparty matching.
- POST /single-documents/:id/assign accepts {project_id} OR
  {new_project: {name, template, counterparty, parent_counterparty}}.

Frontend:
- New /intake route with bulk upload button (multi-file).
- Per-doc row shows role + status + lifecycle pills, counterparty +
  parent + confidence, fuzzy-matched existing project suggestions
  (single click to assign), and a "Create new project" button that
  preselects the right template based on detected role.
- AppSidebar gains Intake entry above Projects.
- Polls every 4s while any doc is mid-analysis.

Projects list now leads with what matters for contract management:
- Replaced CM / Chats columns with Type (vendor/customer/internal pill)
  and Counterparty (with parent badge if any).
- Files + Reviews kept; Created replaced with Updated (more useful).

Intake row improvements:
- "Create new project" now names the project as
  "Counterparty - LIFECYCLE_HINT" when both are known (e.g.
  "Adobe Inc. - SOW") so multiple contracts with one counterparty stay
  distinguishable.
- New "Assign to..." dropdown lists every existing project so you can
  pick a target even when fuzzy-match doesn't surface it.

Backend:
- POST /single-documents/bulk-assign accepts {document_ids, project_id}
  or {document_ids, new_project} and atomically reassigns the batch.
- GET /projects/counterparties now folds standalone documents into the
  customer index. Each group gains a standalone_count field; documents
  without an intake_role match the role filter via intake_role.
- GET /projects/counterparties/:name/timeline includes user-owned
  standalone docs whose intake_counterparty matches.

Frontend (/intake):
- Filter chips by role: All / Vendors / Customers / Internal-Other,
  with per-bucket counts.
- Per-row checkboxes plus a select-all checkbox in the header.
- Sticky bulk-action bar (visible when 1+ selected): pick an existing
  project from a dropdown and "Assign", or "Create new project from
  selection" which auto-derives template + counterparty by majority
  vote across the picked docs.

- CustomersOverview shows '+N standalone' pill on each counterparty row
  when standalone docs exist, plus a footer link "view full timeline"
  in the expanded section.
- Page total now includes a "X standalone docs" tally.
- CounterpartyTimelineView synthesises an "Unassigned" timeline entry
  when standalone docs exist, so visiting /customers/Adobe Inc. with
  no projects but 2 unassigned PDFs actually renders the docs (was
  showing "no projects" empty state).
- Empty-state copy updated for the new world (don't require projects).