feat(tenancies-p6-followup): generic create dialog + edit dialog + self-FKs

- Migration 0086: berth_tenancies.previous_tenancy_id +
  transferred_from_tenancy_id self-FKs + partial indexes. Per
  docs/tenancies-design.md these chain renewal / transfer successors
  to predecessors for fixed-term and seasonal lineage. Schema mirrored
  in tenancies.ts with AnyPgColumn typed-import.
- POST /api/v1/tenancies (generic create): accepts berthId in the
  body so client + yacht tab entry points don't have to bounce through
  /api/v1/berths/[id]/tenancies. Same createPending service helper.
- TenancyCreateDialog: <TenancyCreateDialog open clientId? yachtId?
  berthId? /> with all three pickers; pre-fills the carrier from the
  parent entity. POSTs to /api/v1/tenancies; "Create" and
  "Create and activate" CTAs both wire to the new endpoint.
- Mounted on ClientTenanciesTab + YachtTenanciesTab behind
  <PermissionGate resource="tenancies" action="manage"> so reps can
  mint tenancies directly from those tabs without bouncing through
  the berth page.
- TenancyEditDialog: edit metadata only (start/end dates, tenure type,
  notes) via the new action='update' branch on the [id] PATCH route.
  Status transitions stay on activate/end/cancel. Wired into the
  tenancy detail page header. Outer wrapper unmounts on close so the
  form re-initialises from current row data without setState-in-effect.
- updateTenancy service helper + PATCH action='update' branch added.
  Audit-logged + emits berth_tenancy:activated to invalidate detail
  query caches.

Renew + Transfer dialogs deferred — both need lineage UX decisions
(tenure-aware mutate-in-place vs new-row spawn; client/yacht swap
semantics) and the self-FK columns this commit lands are the
underpinning. Next sub-task.

Verified: tsc clean, 1493/1493 vitest, migration applied.

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

src/lib/db/migrations/0086_tenancies_self_fks.sql

@@ -0,0 +1,14 @@
+-- 0086_tenancies_self_fks.sql
+-- Add self-FKs for renewals + transfers per docs/tenancies-design.md
+-- §"Data model > Rename migration". `previous_tenancy_id` chains a new
+-- row to the row it succeeds (fixed-term + seasonal renewals mint a new
+-- row; permanent renewals mutate in place). `transferred_from_tenancy_id`
+-- chains a new row to the predecessor when an active tenancy is
+-- handed over to a different client/yacht.
+
+ALTER TABLE berth_tenancies
+  ADD COLUMN IF NOT EXISTS previous_tenancy_id text REFERENCES berth_tenancies(id) ON DELETE SET NULL,
+  ADD COLUMN IF NOT EXISTS transferred_from_tenancy_id text REFERENCES berth_tenancies(id) ON DELETE SET NULL;
+
+CREATE INDEX IF NOT EXISTS idx_bt_previous ON berth_tenancies(previous_tenancy_id) WHERE previous_tenancy_id IS NOT NULL;
+CREATE INDEX IF NOT EXISTS idx_bt_transferred_from ON berth_tenancies(transferred_from_tenancy_id) WHERE transferred_from_tenancy_id IS NOT NULL;

src/lib/db/schema/tenancies.ts

@@ -1,4 +1,11 @@
-import { pgTable, text, timestamp, index, uniqueIndex } from 'drizzle-orm/pg-core';
+import {
+  pgTable,
+  text,
+  timestamp,
+  index,
+  uniqueIndex,
+  type AnyPgColumn,
+} from 'drizzle-orm/pg-core';
 import { sql } from 'drizzle-orm';
 import { ports } from './ports';
 import { berths } from './berths';
@@ -43,6 +50,22 @@ export const berthTenancies = pgTable(
     tenureType: text('tenure_type').notNull().default('permanent'),
     contractFileId: text('contract_file_id').references(() => files.id, { onDelete: 'set null' }),
     notes: text('notes'),
+    // Renewal + transfer self-FKs (migration 0086). `previousTenancyId`
+    // chains a successor row to the row it succeeds (fixed-term + seasonal
+    // renewals mint a new row; permanent renewals mutate in place so the
+    // FK stays null). `transferredFromTenancyId` chains a new row to the
+    // predecessor when an active tenancy is handed over to a different
+    // client / yacht. SET NULL on delete keeps the lineage best-effort.
+    previousTenancyId: text('previous_tenancy_id').references(
+      (): AnyPgColumn => berthTenancies.id,
+      {
+        onDelete: 'set null',
+      },
+    ),
+    transferredFromTenancyId: text('transferred_from_tenancy_id').references(
+      (): AnyPgColumn => berthTenancies.id,
+      { onDelete: 'set null' },
+    ),
     createdBy: text('created_by').notNull(),
     createdAt: timestamp('created_at', { withTimezone: true }).notNull().defaultNow(),
     updatedAt: timestamp('updated_at', { withTimezone: true }).notNull().defaultNow(),