docs(claude-md): documents hub split + auto-filed client folders

Extends the Document folders subsection with:
  - Three system roots + per-entity subfolders + lifecycle hooks
    (syncEntityFolderName, applyEntityArchivedSuffix,
    demoteSystemFolderOnEntityDelete).
  - Owner-wins owner resolution in handleDocumentCompleted, adapted
    to the actual interests schema (no primary*Id columns; no
    companyId on interests).
  - Aggregated projection (listFilesAggregatedByEntity +
    listInflightWorkflowsAggregatedByEntity) with symmetric reach,
    file-FK source of truth, defense-in-depth port_id, ended-
    membership filter, signedFromDocumentId reverse-link.
  - Hub UI three render modes (root, entity, flat).
  - Permission gating + deploy sequence (migration 0051 +
    db:backfill:doc-folders).

Smoke project deferred: requires running dev server; specs are
type-checked and committed in Task 18; CI/reviewer to execute.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -94,7 +94,19 @@ src/
 - **Portal auth pages:** `/portal/login`, `/portal/activate`, `/portal/reset-password` and the CRM `/login`, `/reset-password`, `/set-password` all wrap their content in `<BrandedAuthShell>` (`src/components/shared/branded-auth-shell.tsx`) which renders the same blurred background + logo + white card the email templates use, so the in-app and email surfaces look unified.
 - **Inline editing pattern:** detail pages (clients, yachts, companies, interests, residential clients/interests) use `<InlineEditableField>` (`src/components/shared/inline-editable-field.tsx`) for click-to-edit text/select/textarea fields and `<InlineTagEditor>` (`src/components/shared/inline-tag-editor.tsx`) for tag chips. Each entity exposes a `PUT /api/v1/<entity>/[id]/tags` endpoint backed by a `set<Entity>Tags` service helper that wipes-and-rewrites the join table inside a single transaction. There are no separate "Edit" modal forms on detail pages — the entire overview tab is editable in place.
 - **Notes (polymorphic across entity types):** `notes.service.ts` dispatches across `clientNotes`, `interestNotes`, `yachtNotes`, `companyNotes` based on an `entityType` discriminator. `<NotesList entityType="…" />` works for all four. `companyNotes` lacks an `updatedAt` column — the service substitutes `createdAt` so callers get a uniform shape.
-- **Document folders:** Per-port nestable tree (`document_folders` self-FK on `parent_id`; null parent = root). Documents carry a nullable `folder_id` (null = root). Sibling-name uniqueness enforced via `uniq_document_folders_sibling_name` on `(port_id, COALESCE(parent_id, '__root__'), LOWER(name))`. Folder delete is **soft rescue**: `deleteFolderSoftRescue` re-parents every child folder + document up to the deleted folder's parent (or to root) inside a transaction, then drops the folder row — never CASCADE. Cycle prevention in `moveFolder` walks the destination's ancestor chain. All folder ops gated on `documents.manage_folders` (read access piggybacks on `documents.view`).
+- **Document folders:** Per-port nestable tree (`document_folders` self-FK on `parent_id`; null parent = root). Documents and files carry a nullable `folder_id` (null = root). Sibling-name uniqueness via `uniq_document_folders_sibling_name` on `(port_id, COALESCE(parent_id, '__root__'), LOWER(name))`. Folder delete is **soft rescue**: `deleteFolderSoftRescue` re-parents every child folder + document + file up to the deleted folder's parent (or to root) inside a transaction, then drops the folder row — never CASCADE. Cycle prevention in `moveFolder` walks the destination's ancestor chain.
+
+  Three system roots (`Clients/`, `Companies/`, `Yachts/`) are auto-created on port init via `ensureSystemRoots`. Per-entity subfolders are created lazily on first auto-deposit / manual upload via `ensureEntityFolder` — concurrent callers race safely via the partial unique index `uniq_document_folders_entity` on `(port_id, entity_type, entity_id) WHERE entity_id IS NOT NULL`. The `chk_system_folder_shape` CHECK pins the shape of system rows. Rename/move/delete on `system_managed = true` folders is rejected by `assertNotSystemManaged` (service-level, not DB-level). Entity rename auto-syncs the folder name via `syncEntityFolderName`; archive applies a ` (archived)` suffix via `applyEntityArchivedSuffix`; hard-delete demotes (`system_managed = false`) + appends ` (deleted)` via `demoteSystemFolderOnEntityDelete`.
+
+  Auto-deposit on signing completion: `handleDocumentCompleted` resolves the owner via the Owner-wins chain (`document.clientId ?? .companyId ?? .yachtId ?? interest.clientId ?? interest.yachtId`), ensures the matching entity subfolder, and sets `files.folder_id` + the matching entity FK on the signed file row. Falls back to root when no owner is resolvable. (Note: `interests` table has no `companyId` column, hence the chain's interest fallback omits it.)
+
+  Aggregated projection: `listFilesAggregatedByEntity` / `listInflightWorkflowsAggregatedByEntity` walk the relationship graph from the requested entity (symmetric reach: Client ↔ Company via `company_memberships` filtered to active rows via `isNull(end_date)`, ↔ Yacht via `yachts.current_owner_type/id`) and return results grouped by source (DIRECTLY ATTACHED / FROM COMPANY / FROM YACHT / FROM CLIENT). Each group caps at 20 rows with a total for `Show all (N)`. The files projection LEFT JOINs `documents` on `signed_file_id` to surface `signedFromDocumentId` per row — used by the UI's "view signing details" link. **File-FK snapshot is the source of truth** — historical files stay where they were filed even if the linked entity's relationships change. **Defense-in-depth `port_id` filter at every join** (per recommender precedent) — entry-point check alone is rejected. Completed workflows are hidden from folder views (`listDocuments` excludes `status='completed'` when `folderId` is set); the signed-PDF file surfaces in the Files section with a "view signing details" link to the workflow audit trail (via `GET /api/v1/documents/[id]/signing-details`).
+
+  Hub UI: rebuilt around three render modes — `HubRootView` (no folder), `EntityFolderView` (system-managed entity subfolder, renders Signing-in-progress + Files via the aggregated projection), `FlatFolderListing` (any other folder). Sidebar shows lock markers on system folders and mutes archived entity folders. The signing-status tabs strip (`in_progress` / `awaiting_them` / etc.) was removed; folders are now the primary navigation.
+
+  Permission gating: `documents.view` for read of folders + entity-aggregated listing; `documents.manage_folders` for create / rename / move / delete of user folders (system folders are immutable through the API entirely).
+
+  Deploy: schema migration `0051_documents_hub_split.sql` ships the columns; `pnpm db:backfill:doc-folders` (script `scripts/backfill-document-folders.ts`) runs after the migration and is idempotent (per-port `pg_advisory_xact_lock`).
 - **Route handler exports:** Next.js App Router `route.ts` files only allow specific named exports (`GET|POST|…`). Service-tested handler functions live in sibling `handlers.ts` files (e.g. `src/app/api/v1/yachts/[id]/handlers.ts`) and are imported by the colocated `route.ts` for `withAuth(withPermission(...))` wrapping. Integration tests import from `handlers.ts` directly to bypass auth/permission middleware.
 - **Multi-berth interest model:** `interest_berths` is the source of truth for which berths an interest is linked to; `interests.berth_id` does not exist (dropped in migration 0029). Three role flags: `is_primary` (≤1 row per interest, enforced by partial unique index — surfaces as "the berth for this deal" in templates / forms / list views), `is_specific_interest` (true → berth shows as "Under Offer" on the public map; false → legal/EOI-only link), `is_in_eoi_bundle` (covered by the interest's EOI signature). Read/write through `src/lib/services/interest-berths.service.ts` helpers (`getPrimaryBerth`, `getPrimaryBerthsForInterests`, `upsertInterestBerth`, `setPrimaryBerth`, `removeInterestBerth`); never query `interest_berths` from outside that service.
 - **Mooring number canonical format:** `^[A-Z]+\d+$` (e.g. `A1`, `B12`, `E18`) — no hyphen, no leading zeros. Stored, displayed, URL-encoded, and rendered in EOIs in this exact form. Phase 0 normalized the entire CRM dataset; the mooring-pattern regex gates the public `/api/public/berths/[mooringNumber]` route before any DB hit.