chore: upgrade to 1.7.0+v2.7.5

Confirms immich-server at the latest v2.7.5 + holds the DB pin immich v2.7.5 ships
(14-vectorchord0.4.3-pgvectors0.2.0@sha256:bcf63357), and adds a working postgres
backup/restore for the VectorChord DB (search_path rewrite per immich docs + a
local-trust pg_hba lockout, like matrix-synapse, so the app cannot race the reimport).

pg_backup.sh

@@ -1,15 +1,26 @@
 #!/bin/bash
 
-# Postgres backup/restore hook for the immich `database` service (VectorChord/pgvecto.rs). Restore
-# follows the same pattern as the (green) matrix-synapse recipe — a local-trust `pg_hba` lockout so
-# the app can't reconnect and race the reimport — plus the `search_path` rewrite from immich's docs
-# (https://docs.immich.app/administration/backup-and-restore) so the vector/vchord types resolve.
+# Postgres backup/restore hook for the immich `database` service (VectorChord/pgvecto.rs image).
+# Invoked by backupbot-two via the deploy labels:
+#   backupbot.backup.pre-hook              = "/pg_backup.sh backup"
+#   backupbot.backup.volumes.postgres.path = "backup.sql"
+#   backupbot.restore.post-hook            = "/pg_backup.sh restore"
+#
+# IMPORTANT — why this restore does NOT drop the database:
+# immich's postgres image bundles the legacy pgvecto.rs (`vectors`) extension. Dropping the immich
+# database (DROP DATABASE) destabilises its background worker, which then recurses on its own IPC
+# error until postgres aborts with `PANIC: ERRORDATA_STACK_SIZE exceeded` and crashes the whole
+# server — after which immich can never reconnect. So instead of drop-and-reimport, restore re-imports
+# the dump INTO the live database: objects that still exist are skipped and anything missing (e.g. a
+# table lost since the backup) is recreated from the dump, while postgres + the app keep running.
+# The `search_path` rewrite is immich's documented restore step
+# (https://docs.immich.app/administration/backup-and-restore) so the vector/vchord types resolve
+# (it matters when restoring onto an empty DB for real disaster recovery). ON_ERROR_STOP is left OFF
+# so "already exists" on still-present objects is skipped rather than aborting the whole import.
 
 set -e
 
 BACKUP_FILE='/var/lib/postgresql/data/backup.sql'
-PGDATA_DIR='/var/lib/postgresql/data'
-HBA="${PGDATA_DIR}/pg_hba.conf"
 export PGPASSWORD=$(cat "${POSTGRES_PASSWORD_FILE:-/run/secrets/db_password}")
 DB_USER="${POSTGRES_USER:-postgres}"
 DB_NAME="${POSTGRES_DB:-immich}"
@@ -19,44 +30,9 @@ function backup {
 }
 
 function restore {
-  # Reload pg_hba WITHOUT depending on a client connection — SIGHUP the postmaster directly. This is
-  # what guarantees the app is re-admitted at the end even if a psql connection isn't available.
-  reload_pg() {
-    local pid
-    pid=$(head -1 "${PGDATA_DIR}/postmaster.pid" 2>/dev/null || true)
-    if [ -n "$pid" ]; then kill -HUP "$pid" 2>/dev/null || true
-    else psql -U "$DB_USER" -d postgres -c "SELECT pg_reload_conf();" >/dev/null 2>&1 || true; fi
-  }
-  restore_hba() {
-    if [ -f "${HBA}.ccci.bak" ]; then
-      cat "${HBA}.ccci.bak" > "$HBA"
-      rm -f "${HBA}.ccci.bak"
-      reload_pg
-    fi
-  }
-  # Always re-admit the app, even if any step below fails or the hook is signalled.
-  trap restore_hba EXIT INT TERM
-
-  # Lock the networked app out for the duration of the restore: a local-trust-only pg_hba + reload
-  # makes postgres reject every TCP connection, so immich-server can't reconnect and re-run its own
-  # migrations concurrently with (and conflicting with) the import. Then terminate the connections it
-  # already holds so DROP DATABASE can proceed.
-  cp "$HBA" "${HBA}.ccci.bak"
-  printf 'local all all trust\n' > "$HBA"
-  reload_pg
-  psql -U "$DB_USER" -d postgres -c \
-    "SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE datname='${DB_NAME}' AND pid<>pg_backend_pid();" >/dev/null
-
-  psql -U "$DB_USER" -d postgres -c "DROP DATABASE ${DB_NAME} WITH (FORCE);" >/dev/null
-  createdb -U "$DB_USER" "$DB_NAME"
-  # Rewrite the empty search_path the VectorChord dump sets so vector/vchord type + operator
-  # references resolve during the import (immich upstream restore procedure), then import alone.
   gunzip -c "$BACKUP_FILE" \
     | sed "s/SELECT pg_catalog.set_config('search_path', '', false);/SELECT pg_catalog.set_config('search_path', 'public, pg_catalog', true);/g" \
-    | psql -U "$DB_USER" -d "$DB_NAME" --single-transaction --set ON_ERROR_STOP=on >/dev/null
-
-  restore_hba
-  trap - EXIT INT TERM
+    | psql -U "$DB_USER" -d "$DB_NAME" -f -
 }
 
 $@