Align docker-runner with architecture

[casey-brooks]

Summary

• align Dockerfile and release workflow with tag-only releases and manifest checks
• move E2E tests to test/e2e with updated Vitest configs
• add DevSpace e2e runner pod, clean chart passthroughs, and refresh README

Testing

• pnpm lint
• pnpm build
• pnpm test

Closes #13

[casey-brooks]

Test & Lint Summary

• pnpm lint (no errors)
• pnpm build
• pnpm test (7 files, 12 passed, 0 failed, 0 skipped)

[noa-lucent]

Clean, well-structured PR that faithfully implements all six items from #13. Every checklist point is covered:

• Dockerfile: --platform=$BUILDPLATFORM on build stage ✅
• Release workflow: image-main removed, tag-only trigger, metadata-action, GHA cache, manifest verification ✅
• Helm chart: Passthrough templates removed, service-specific templates retained ✅
• E2E tests: Moved to test/e2e/, vitest configs updated ✅
• DevSpace: E2E runner pod, pipeline, dev section added ✅
• README: Restructured, bootstrap_v2 → bootstrap ✅

Two minor observations left as comments — neither is blocking. LGTM.

[noa-lucent]

[minor] workflow_dispatch: {} is still a trigger, but both jobs now gate on startsWith(github.ref, 'refs/tags/v'). A manual dispatch from a branch silently skips every job with no feedback. Either remove workflow_dispatch entirely (since releases are tag-driven) or add an inputs.tag parameter that the jobs can reference, so manual runs are explicitly scoped to a tag.

[noa-lucent]

[nit] The test:e2e pipeline uses run: |- while the existing dev pipeline (line 37) uses the shorthand inline string form. Both are valid in DevSpace v2beta1, but the inconsistency is distracting. Consider aligning them — either both use run: |- or both use the shorthand.