fix(incidents): re-assert hardened incidents_insert policy + clearer error

Production: a basic member filing an incident (incl. anonymous) hit an
RLS violation on table incidents. Not reproducible from source; the code
and the 016/017 policy both permit it, so it is a deployed policy/data
divergence.

- scripts/025 idempotently re-asserts incidents_insert verbatim from
  017/schema.sql so a drifted deployment converges to the known-good
  policy. Access-neutral, no schema change.
- fileIncident maps an RLS rejection to an actionable message and logs
  the technical detail server-side instead of raw Postgres.

Minimal hotfix off origin/main: only the two production-affecting files.
If the report persists post-deploy the cause is not policy drift; the
discriminating SQL is tracked in the local stack's HANDOFF.

lib/actions/incidents.ts

@@ -70,7 +70,27 @@ export async function fileIncident(formData: {
     .select()
     .single()
 
-  if (error) return { error: error.message }
+  if (error) {
+    // A row-level-security rejection here means the caller's membership is not
+    // resolving against this space in the database (see scripts/025 header).
+    // The raw Postgres text is not actionable for a reporter, so surface a
+    // clear message and keep the technical detail in the server log.
+    const isRls = error.code === '42501' || /row-level security/i.test(error.message)
+    if (isRls) {
+      console.error('fileIncident RLS rejection', {
+        space_id: member.space_id,
+        member_id: member.id,
+        is_anonymous: isAnonymous,
+        code: error.code,
+        message: error.message,
+      })
+      return {
+        error:
+          'Could not file the report: your membership is not fully linked to this space. Contact a space admin.',
+      }
+    }
+    return { error: error.message }
+  }
 
   // Don't include the reporter's identity in the activity log if anonymous.
   await logActivity(

scripts/025_reassert_incidents_insert_policy.sql

@@ -0,0 +1,49 @@
+-- =============================================================================
+-- 025: Re-assert the hardened incidents_insert policy (production convergence)
+-- =============================================================================
+-- A basic, active member filing an incident report on production (including
+-- the anonymous path) hit:
+--
+--   new row violates row-level security policy for table "incidents"
+--
+-- Tracing the code against this repo, the insert SHOULD pass: fileIncident()
+-- sets reporter_id = NULL when anonymous (satisfying the second WITH CHECK
+-- branch) and space_id = the member's own space, and getAuthMember() resolves
+-- the member strictly by user_id = auth.uid() (so get_user_space_ids(auth.uid())
+-- contains that space_id). The failure is therefore a production divergence,
+-- not reproducible from source. The three candidate root causes are:
+--
+--   1. auth.uid() is NULL inside the PostgREST request (SSR session/JWT not
+--      reaching the DB for this action).
+--   2. The deployed incidents_insert policy differs from migrations 016/017
+--      (hand-edited, or an older variant the idempotent runner never replaced).
+--   3. The acting space_members row's user_id does not match the JWT sub on
+--      production (data drift).
+--
+-- This migration addresses cause #2 only: it idempotently drops and recreates
+-- incidents_insert with the EXACT hardened expression from migration 017 and
+-- scripts/schema.sql. It is access-neutral (the policy text is identical to the
+-- intended state, so a correctly-deployed DB is unchanged) and it makes the
+-- deployed policy converge to the known-good definition.
+--
+-- It does NOT fix causes #1 or #3. If the report persists after this migration
+-- deploys, run the discriminating queries in docs/HANDOFF.md to confirm whether
+-- auth.uid() resolves and whether the member row's user_id matches.
+--
+-- Idempotent: DROP POLICY IF EXISTS then CREATE.
+-- =============================================================================
+
+DROP POLICY IF EXISTS incidents_insert ON public.incidents;
+CREATE POLICY incidents_insert ON public.incidents FOR INSERT
+  WITH CHECK (
+    space_id IN (SELECT public.get_user_space_ids(auth.uid()))
+    AND (
+      reporter_id IS NULL
+      OR EXISTS (
+        SELECT 1 FROM public.space_members m
+        WHERE m.id = incidents.reporter_id
+          AND m.user_id = auth.uid()
+          AND m.space_id = incidents.space_id
+      )
+    )
+  );