init: project structure, .gitignore, .env.example, runners.conf.example

- .gitignore: excludes .env, runners.conf, certs, temp files, editor files
- .env.example: all configuration variables with sections and descriptions
- runners.conf.example: dynamic runner definition format (pipe-delimited)
- PLAN.md: comprehensive implementation plan with DoD for all 18 milestones
- CLAUDE.md: project conventions and instructions

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.claude/settings.json

@@ -0,0 +1,5 @@
+{
+  "permissions": {
+    "allow": ["Bash(*)"]
+  }
+}