fix(db): live-row partial unique for intake re-take, mood external-id dedup key, perf indexes

Migration 0121 replaces the MedicationIntakeEvent unique constraint with a
partial unique index `WHERE deleted_at IS NULL`. A slot the user previously
deleted (tombstoned) no longer occupies the unique slot, so a re-take
re-creates the row cleanly instead of P2002-ing against the tombstone and
500-ing. The migration dedups any pre-existing duplicate live rows first
(keep newest, tombstone the rest) so the unique build can't fail on real
data.

Measurement and Workout deliberately stay full uniques: Measurement's
compound-key writes use prisma.upsert, which Prisma 7 compiles to native
INSERT ... ON CONFLICT and Postgres cannot arbiter against a partial unique
(and consolidate-daily-mean intentionally resurrects a tombstoned canonical
row, which needs the full unique); Workout has no deleted_at column. The
rationale is documented in the migration header and the schema comments.

Migration 0122 adds MoodEntry.externalId plus a NULL-distinct
`@@unique([userId, source, externalId])`. The moodLog webhook, the pull sync,
and the JSON import now carry the source's stable id into externalId and
upsert on the new key when present, so a re-import is idempotent even when
moodLoggedAt re-rounds or re-zones. Native/MANUAL entries keep their NULL
externalId and stay on the legacy (userId, date, moodLoggedAt) path.

Migration 0123 adds AuditLog(userId, action, createdAt desc) and
MoodEntry(userId, moodLoggedAt) composite indexes for the status-cache and
mood-insights read paths.

Also corrects the stale "v1.6.0 drops this column" note on
MedicationSchedule.daysOfWeek (the column is still dual-written and read by
live paths, so it is retained) and documents the UTC-only timezone storage
invariant in a schema header comment.

Integration tests cover the intake re-take after delete (no resurrection /
no 500) and mood re-import idempotency (with and without an external id) on
real Postgres.

(cherry picked from commit 9a6723f469bdec063a99cd08df132e07ec3c95a5)

src/app/api/integrations/moodlog/webhook/route.ts

@@ -95,18 +95,54 @@ export const POST = apiHandler(async (request: NextRequest) => {
 
   // 5. Process event (non-blocking — fire and forget with error logging)
   const moodLoggedAt = new Date(entry.time);
+  // v1.12.1 — when the upstream supplies a stable entry id, dedup on
+  // `(userId, source, externalId)` so a re-emit with a re-rounded /
+  // re-zoned `time` updates the same row instead of minting a duplicate.
+  // Absent → the legacy `(userId, date, moodLoggedAt)` key. MOODLOG is
+  // the fixed source here, matching the create/update writes below.
+  const externalId = entry.id ?? null;
 
   try {
     if (event === "mood.deleted") {
       await prisma.moodEntry.deleteMany({
         where: {
           userId: user.id,
+          ...(externalId
+            ? { source: "MOODLOG", externalId }
+            : { date: entry.date, moodLoggedAt }),
+        },
+      });
+    } else if (externalId) {
+      // mood.created or mood.updated, keyed on the stable external id.
+      await prisma.moodEntry.upsert({
+        where: {
+          userId_source_externalId: {
+            userId: user.id,
+            source: "MOODLOG",
+            externalId,
+          },
+        },
+        update: {
+          mood: entry.mood,
+          score: entry.score,
+          tags: entry.tags ? JSON.stringify(entry.tags) : null,
+          source: "MOODLOG",
           date: entry.date,
           moodLoggedAt,
         },
+        create: {
+          userId: user.id,
+          date: entry.date,
+          mood: entry.mood,
+          score: entry.score,
+          tags: entry.tags ? JSON.stringify(entry.tags) : null,
+          source: "MOODLOG",
+          externalId,
+          moodLoggedAt,
+        },
       });
     } else {
-      // mood.created or mood.updated
+      // mood.created or mood.updated, legacy wall-clock key.
       await prisma.moodEntry.upsert({
         where: {
           userId_date_moodLoggedAt: {