andrew/fix testing local verify

[ayjayt]

• Add diagnostics.
• Fix publish to not use sources.
• Only allow publish on attempt 1.
• Remove uv python pin from GHA, dirties folder.
• Add option to enable debug via env var.
• Improve debug mode.
• Fix: env vars always strings.
• Add testing canary to see if we're using testable chrome.
• Print sys.path in stderr in canary.
• Change pytest import mode to append.
• Change pytest import mode to append (FIX).
• Adjust poethepoet path alteration.
• Update regular tests to enable debug.
• Add locked to GHA