fix: compare launchd configuration literally

[aikinley]

Summary

• compare launchd configuration values as fixed strings instead of regular expressions
• ensure auth/client/audience/autospin/local/plugin-version drift triggers the required companion restart
• update all three shipped launcher mirrors
• add an isolated Darwin-branch regression for a regex-equivalent but different auth URL

Why

The default auth URL contains dots. In v0.1.54, grep -q treats those dots as wildcards, so the requested https://auth.monk.io incorrectly matches a stored https://auth-monk-io. The healthy fast path then reports success while reusing a companion with stale authentication configuration.

Validation

• pristine v0.1.54 regression: exits 1 because no launchd restart occurs
• fixed regression: tests/start-monk-agent-launchd-regex-drift.sh passes
• existing tests/start-monk-agent-fastpath.sh passes
• existing tests/start-monk-agent-readiness-timeout.sh passes
• C:\Program Files\Git\bin\bash.exe -n scripts/start-monk-agent.sh
• SHA-256 equality verified across all three launcher mirrors
• git diff --check

Generated artifacts

GENERATED.md says the public tree is generated from the private monk-agent/plugin source. This PR updates the mirrored public artifacts consistently; the corresponding source change should be ported before the next regeneration.

Fixes #256