feat(helm): add extraObjects support to deploy supplementary resources

[gbrd]

Add a new extraObjects value to the Plik Helm chart, allowing users to deploy arbitrary Kubernetes manifests alongside the chart (e.g. ExternalSecrets, NetworkPolicies, RBAC rules).
Three input forms are supported via templates/extra-objects.yaml:

• dict (default, recommended): Helm deep-merges dicts across multiple -f files, so each values file can independently add its own named key without overwriting keys from other files.
• list: convenient for a single values file; a second -f replaces the entire list.
• string: same last-file-wins behaviour as a list, but the whole block is evaluated through tpl first — useful for inline Go template expressions (e.g. {{ include "plik.fullname" . }}). All three forms pass manifests through tpl before rendering. Update ARCHITECTURE.md with a comparison table and CHANGELOG.md with an [Unreleased] entry.

[gbrd]

no news about this ?

[bodji]

Thanks for the PR, the feature itself is clean and works well. I checked it out locally (helm lint + helm template for all three forms; the dict/list/string variants all render correctly and tpl resolves helpers like {{ include "plik.fullname" . }}). Two things before this can go green:

1. CI helm-docs check will fail (blocking).
The # -- annotation was added to values.yaml, but charts/plik/README.md wasn't regenerated. The helm-docs job in .github/workflows/tests.yaml runs make helm-docs then git diff --exit-code, and I confirmed locally that it produces a diff (adds the missing extraObjects row). Fix:

make helm-docs
git add charts/plik/README.md

2. The generated README table cell is unreadable (recommended).
Because the whole multi-form example block follows # --, helm-docs slurps all ~40 lines into a single Values-table cell, producing one giant blob. Consider making the # -- line a short one-liner and demoting the long examples to plain # comments (not # --), e.g.:

# -- (object) Extra Kubernetes manifests to deploy alongside the chart.
# See ARCHITECTURE.md for the three supported forms (dict / list / string).
# Examples:
#   extraObjects:
#     my-secret: { ... }
extraObjects: {}

Nice work otherwise, the dict-for-mergeability rationale and the docs are excellent.

[gbrd]

done. may I squash the 2 commits ?