feat(media-supply): persist favorites with multi-group membership

Move media favorites from client state to PostgreSQL with server-side
search and pagination.

- Store favorites keyed by (tenant, user, group, resource) so a resource
  can belong to multiple groups; the 500-resource cap counts distinct
  resources, not memberships.
- Add favorite-group CRUD and group/global removal routes, with silent
  cleanup of delisted or invisible resources on read.
- Serve favorite resource details server-side, 10 per page, with name/ID
  search; favorites-page removal is group-scoped, resources-page removal
  is global.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

server/migrations/20260710183000_create_media_supply_favorites.down.sql

@@ -0,0 +1,3 @@
+DROP TABLE IF EXISTS media_supply_favorite_resources;
+DROP TABLE IF EXISTS media_supply_favorite_groups;
+DROP TABLE IF EXISTS media_supply_favorite_owners;

server/migrations/20260710183000_create_media_supply_favorites.up.sql

@@ -0,0 +1,57 @@
+CREATE TABLE IF NOT EXISTS media_supply_favorite_owners (
+    tenant_id  BIGINT NOT NULL REFERENCES tenants(id) ON DELETE CASCADE,
+    user_id    BIGINT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    revision   BIGINT NOT NULL DEFAULT 0,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    PRIMARY KEY (tenant_id, user_id),
+    CONSTRAINT chk_media_supply_favorite_owner_revision CHECK (revision >= 0)
+);
+
+CREATE TABLE IF NOT EXISTS media_supply_favorite_groups (
+    tenant_id  BIGINT NOT NULL,
+    user_id    BIGINT NOT NULL,
+    group_key  VARCHAR(64) NOT NULL,
+    name       VARCHAR(64) NOT NULL,
+    sort_order INTEGER NOT NULL DEFAULT 0,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    PRIMARY KEY (tenant_id, user_id, group_key),
+    CONSTRAINT fk_media_supply_favorite_group_owner
+        FOREIGN KEY (tenant_id, user_id)
+        REFERENCES media_supply_favorite_owners (tenant_id, user_id)
+        ON DELETE CASCADE,
+    CONSTRAINT chk_media_supply_favorite_group_key_not_blank CHECK (BTRIM(group_key) <> ''),
+    CONSTRAINT chk_media_supply_favorite_group_name_not_blank CHECK (BTRIM(name) <> '')
+);
+
+CREATE UNIQUE INDEX IF NOT EXISTS uk_media_supply_favorite_group_name
+    ON media_supply_favorite_groups (tenant_id, user_id, LOWER(name));
+
+CREATE INDEX IF NOT EXISTS idx_media_supply_favorite_group_owner_order
+    ON media_supply_favorite_groups (tenant_id, user_id, sort_order, created_at);
+
+CREATE TABLE IF NOT EXISTS media_supply_favorite_resources (
+    tenant_id   BIGINT NOT NULL,
+    user_id     BIGINT NOT NULL,
+    group_key   VARCHAR(64) NOT NULL,
+    resource_id BIGINT NOT NULL REFERENCES supplier_media_resources(id) ON DELETE CASCADE,
+    created_at  TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    PRIMARY KEY (tenant_id, user_id, group_key, resource_id),
+    CONSTRAINT fk_media_supply_favorite_resource_group
+        FOREIGN KEY (tenant_id, user_id, group_key)
+        REFERENCES media_supply_favorite_groups (tenant_id, user_id, group_key)
+        ON DELETE CASCADE
+);
+
+CREATE INDEX IF NOT EXISTS idx_media_supply_favorite_group_page
+    ON media_supply_favorite_resources (
+        tenant_id,
+        user_id,
+        group_key,
+        created_at DESC,
+        resource_id DESC
+    );
+
+CREATE INDEX IF NOT EXISTS idx_media_supply_favorite_resource_lookup
+    ON media_supply_favorite_resources (resource_id, tenant_id, user_id);