[PM-26337] Create a Claude markdown file (#16676)

* Initial claude markdown with lots of help from the team.

apps/cli/CLAUDE.md

@@ -0,0 +1,13 @@
+# CLI - Critical Rules
+
+- **ALWAYS** output structured JSON when `process.env.BW_RESPONSE === "true"`
+  - Use Response objects (MessageResponse, ListResponse, etc.) from `/apps/cli/src/models/response/`
+  - DON'T write free-form text that breaks JSON parsing
+
+- **NEVER** use `console.log()` for output
+  - Use `CliUtils.writeLn()` to respect `BW_QUIET` and `BW_RESPONSE` environment variables
+  - Use the `ConsoleLogService` from the `ServiceContainer`
+
+- **ALWAYS** respect `BW_CLEANEXIT` environment variable
+  - Exit code 0 even on errors when `BW_CLEANEXIT` is set
+  - Required for scripting environments that need clean exits