fix(init): consolidate scaffold templates and gitignore .astro/*.local.{yml,yaml}

[jlaneve]

Summary

The original two-line gitignore change in this PR was a no-op: astro dev init (and astro-desktop, which scaffolds via the same module) both go through pkg/airflowrt.Scaffold, not through airflow/include/airflow{2,3}/gitignore. The Af{2,3}Gitignore embed vars in airflow/airflow.go had no consumers — so the new lines never reached scaffolded projects.

This PR fixes that and removes the dead duplicate template tree so the same kind of drift can't happen again.

Commits

1. fix(init): apply gitignore additions to airflowrt source-of-truth — moves the .astro/*.local.yml / .astro/*.local.yaml additions to pkg/airflowrt/include/gitignore, which is what astro dev init actually reads. Reverts the no-op additions in airflow/include/airflow{2,3}/gitignore.

2. chore(airflow): remove duplicate scaffold templates — deletes the dead Af{2,3}* embeds in airflow/airflow.go and the corresponding files in airflow/include/airflow{2,3}/. After this, the only remaining live embeds are Af2MonitoringDag (used by cloud/deploy) and Af{2,3}Composeyml (used by airflow/container.go); everything else routes through pkg/airflowrt. ~900 lines of stale duplicate templates removed.

After this, pkg/airflowrt/include is the single source of truth for project scaffolding, shared by astro-cli and external consumers like astro-desktop.

Notes for review

• The cli's dead airflow/include/airflow3/dockerfile had hardcoded the astrocrpublic.azurecr.io/ registry; airflowrt's uses configurable %s placeholders. No behavior change since cli's was unread, but worth flagging — the airflowrt version is the live one.
• airflow/airflow.Init(...) already calls airflowrt.Scaffold(...) (since the pkg/airflowrt extraction); this PR just removes the now-unused embedded copies.

Test plan

• go build ./... passes
• go vet passes for ./airflow/..., ./cloud/deploy/..., ./cmd/..., ./pkg/airflowrt/...
• go test ./pkg/airflowrt/... passes
• go test ./cmd/... passes
• go test ./cloud/deploy/... passes
• go test ./airflow/... — pre-existing podman/docker env-detection failures on main are unchanged; not introduced by this PR
• Run astro dev init in an empty dir and confirm .astro/*.local.yml and .astro/*.local.yaml appear in the generated .gitignore
• Drop a .astro/foo.local.yml and verify git status ignores it

🤖 Generated with Claude Code

[coveralls-official]

Coverage Report for CI Build 6

Coverage remained the same at 39.746%

Details

• Coverage remained the same as the base build.
• Patch coverage: No coverable lines changed in this PR.
• No coverage regressions found.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

No coverage regressions found.

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Coverage Stats

Relevant Lines:	65899
Covered Lines:	26192
Line Coverage:	39.75%
Coverage Strength:	9.41 hits per line

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💛 - Coveralls