-- Phase 1 of the nested document subfolders feature (master UAT line 728+):
--
-- 1. Add a nullable `interest_id` column to `files` so uploads scoped
--    to a deal can be filed under the interest subfolder while still
--    rolling up to the parent client folder. Mirrors the existing
--    `documents.interest_id` semantics: scoping FK that holds a
--    "from-interest" attribution even when the parent client/yacht/
--    company shifts.
--
-- 2. Index on `(port_id, interest_id)` for the aggregated-projection
--    queries that will surface "this-deal" files vs "from-client" files
--    in InterestDocumentsTab.
--
-- 3. Soft FK (`ON DELETE SET NULL`) so a hard-deleted interest doesn't
--    orphan the file — the audit trail stays intact and the file remains
--    findable under the parent client folder.
--
-- Apply in dev:
--   PGPASSWORD=changeme psql -h localhost -p 5434 -U crm -d port_nimara_crm \
--     -f src/lib/db/migrations/0078_files_interest_id.sql

ALTER TABLE files
  ADD COLUMN IF NOT EXISTS interest_id text
    REFERENCES interests(id) ON DELETE SET NULL;

CREATE INDEX IF NOT EXISTS idx_files_interest
  ON files (interest_id);

CREATE INDEX IF NOT EXISTS idx_files_port_interest
  ON files (port_id, interest_id);