re-pin moving tags so Renovate can track them

Renovate can't propose updates for moving tags (the tag string never
changes; the registry just points it at a different image). These three
were pinned to moving variants:

  felhom-system/webpage.yaml : filebrowser/filebrowser:v2-alpine
  felhom-system/umami.yaml   : ghcr.io/umami-software/umami:postgresql-latest
  tandoor-system/tandoor.yaml: vabene1111/recipes:2.6

Pin each to the current actual version per Viktor's call:
  - filebrowser -> v2.63.13 (matches the other 4 filebrowser pinnings
    in the repo; dropped the `-alpine` variant so Renovate can group
    them via the existing default datasource path)
  - umami       -> postgresql-v1.38.0 (current upstream postgresql
    variant latest; tracked via new customManager below)
  - recipes     -> 2.6.9 (current actual semver of the 2.6 series)

For umami, the `postgresql-vX.Y.Z` tag pattern is rejected by Renovate's
default docker versioning pre-check (same failure class as termix +
linuxserver servarr). Added a customManager regex + packageRule disable
pair so Renovate can track future `postgresql-vX.Y.Z` updates via regex
versioning. filebrowser and recipes use standard semver `X.Y.Z` after
the re-pin and need no special handling.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tandoor-system/tandoor.yaml

@@ -30,7 +30,7 @@ spec:
     spec:
       initContainers:
         - name: create-superuser
-          image: vabene1111/recipes:2.6
+          image: vabene1111/recipes:2.6.9
           workingDir: /opt/recipes
           command:
             - /bin/sh
@@ -106,7 +106,7 @@ spec:
                   key: email
       containers:
         - name: tandoor
-          image: vabene1111/recipes:2.6
+          image: vabene1111/recipes:2.6.9
           imagePullPolicy: IfNotPresent
           env:
             - name: TZ