fix(static-site): resolve vendored common subchart dependency (unblocks Release)

[darkobas2]

Problem

The Release workflow has failed on every push to master since 2026-08-02:

Error: directory /home/runner/work/helm/helm/charts/common not found

chart-releaser runs helm dependency update, which tries to resolve
static-site's dependency on the common library chart. Chart.yaml carried
upstream's repository: file://../common — a path that points at a sibling
charts/common directory in the onechart monorepo. No such directory exists in
this repo, so resolution fails and the release job aborts for every chart,
not just static-site.

The subchart was vendored, but as a packaged charts/common-0.7.0.tgz. That
satisfies helm template and helm install — which is why deployments kept
working and this went unnoticed for ten days — but not dependency resolution.

Today's merge of #234 didn't cause this; it was simply the first push to
master since the breakage, so it surfaced it.

Fix

Match the convention beeport-ui already uses in this repo:

• repository: file://../common → repository: file://charts/common
• vendor the subchart as an unpacked charts/common/ directory instead of a tarball

Verification

Against a clean clone:

Check	Before	After
helm dependency update	fails	passes, idempotent on repeat runs
helm lint	passes	passes
helm package	—	passes
helm template	2 objects	2 objects, diff identical

No template or values changes. Chart version is bumped 0.73.0 -> 0.73.1
because chart-testing enforces a version bump on any modified chart; the only
resulting difference in rendered output is the helm.sh/chart label.
PROVENANCE.md records that templates remain upstream v0.73.0 verbatim.

Also included

chart-testing had never run against this chart — the original vendoring
was pushed straight to master without a PR — so it surfaced three further
gates the moment the chart counted as changed:

• version bump required by ct for any modified chart (0.73.0 -> 0.73.1)
• yamllint: two trailing-whitespace occurrences in the vendored values.yaml
• maintainers/home/icon metadata, which upstream shipped without and every
  other chart here carries
• ci/ct-values.yaml: the defaults clone an archived org's demo app and run
  a full npm install && npm run build, so ct install crash-looped the init
  container. The CI values clone this repository and emit a trivial asset,
  exercising the same clone -> build -> copy path. buildImage stays at the
  chart's default node:latest, so no new image dependency.

Origin

Introduced in d631deb ("feat(static-site): vendor onechart static-site chart
v0.73.0") — the packaged subchart was copied across but upstream's file://
path was left pointing at a layout that doesn't exist here.