immich: harden against bulk-import load (memory + probe + Job retries)

Mid-flight stability changes from the 2026-05-24 Anca-elements import
that surfaced multiple latent issues under sustained load:

- `immich-postgresql` memory 3Gi → 5Gi. The original limit OOM-killed
  PG once the bulk insert + vector embeddings drove buffer pressure
  past 3 GiB. 5 GiB gives ~60% headroom over the observed steady
  state during ongoing imports.
- `immich-server` startup probe `failure_threshold` 30 → 360 (5min →
  1h). After any PG restart, immich-server reindexes `clip_index` +
  `face_index` (147k + 185k rows at the time of incident) before
  binding the API port. The old 5min budget was too tight, so each
  PG bounce trapped immich-server in a startup crashloop until the
  reindex was killed. 1h gives generous headroom.
- `kubernetes_job_v1.anca_elements_import.backoff_limit` 2 → 20 and
  `--concurrent-tasks` 8 → 20 on the immich-go upload. Short
  cluster blips (PG restart, KCM lease loss) were exhausting the
  Job's 3-attempt budget. 20 attempts + 20 parallel hashers makes
  dedup-on-resume ~2.5x faster and tolerates a much rougher cluster.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

stacks/immich/main.tf

@@ -321,7 +321,12 @@ resource "kubernetes_deployment" "immich_server" {
             }
             period_seconds    = 10
             timeout_seconds   = 1
-            failure_threshold = 30
+            # Bumped 30 → 360 (5min → 1h): after a PG restart, immich-server
+            # reindexes the clip_index + face_index vector tables before binding
+            # the API port. Hundreds of thousands of rows take longer than 5min
+            # on a cold cache, so the old threshold trapped us in a startup
+            # crashloop after every PG restart (2026-05-24 incident).
+            failure_threshold = 360
             success_threshold = 1
           }
 
@@ -526,10 +531,10 @@ resource "kubernetes_deployment" "immich-postgres" {
           resources {
             requests = {
               cpu    = "100m"
-              memory = "3Gi"
+              memory = "5Gi"
             }
             limits = {
-              memory = "3Gi"
+              memory = "5Gi"
             }
           }
         }
@@ -906,7 +911,7 @@ resource "kubernetes_job_v1" "anca_elements_import" {
   wait_for_completion = false
 
   spec {
-    backoff_limit              = 2
+    backoff_limit              = 20
     ttl_seconds_after_finished = 604800
     template {
       metadata {
@@ -948,7 +953,7 @@ resource "kubernetes_job_v1" "anca_elements_import" {
                 --ban-file "csp/" --ban-file "KOREAN/" \
                 --ban-file "System Volume Information/" \
                 --pause-immich-jobs=false \
-                --concurrent-tasks 8 \
+                --concurrent-tasks 20 \
                 --client-timeout 1h \
                 --no-ui \
                 --on-errors continue