Remove public ingress alert issue URL routing

[cbusillo]

Summary

• Remove lane health-check alert_issue_url as a current public-ingress notification authority.
• Keep historical product profile payloads readable by stripping legacy alert_issue_url during filesystem/Postgres profile read migration.
• Route CLI and FastAPI public-ingress monitor notifications through DB-backed notification drivers instead of legacy standing issue comments.
• Update records docs and tests for the v2 cleanup boundary.

Refs #985
Refs #1322

Verification

• Final review agents: green, no blocking findings.
• uv run python -m unittest (2,764 tests): passed.
• uv run --extra dev ruff check .: passed.
• uv run --extra dev ruff format --check <changed files>: passed.
• uv run --extra dev mypy control_plane tests: passed.
• uv run launchplane service audit-config-authority --control-plane-root .: status ok; existing broad scanner findings unchanged/outside this slice.
• JetBrains changed-files closeout: clean, 0 problems.

Notes

• Repo-wide ruff format --check . still reports pre-existing unrelated formatting drift in 55 files; changed files are formatted.