feat(engine): platform self-awareness, event pipeline fix, globals() builtin, prompt templates

Session 9 changes driven by live trace analysis:

- CodeAct event pipeline: handle_execute_code_step now transfers
  CodeExecutionResult events to thread.events and broadcasts via event_tx
  (fixes false-positive no_tools_used trace warnings)
- Monty globals()/locals() builtins: returns dict of available action names
  from capability leases, enabling "tool_name" in globals() probing
- PlatformInfo injection into system prompts (version, LLM backend, model,
  database, channels, owner, repo URL)
- Mission goal prompts moved to prompts/*.md files (include_str! pattern)
- /expected command for triggering self-improvement from user feedback
- Session 9 development history

Co-Authored-By: Claude Opus 4.6 (1M context) <[email protected]>

CLAUDE.md

@@ -24,6 +24,7 @@ E2E tests: see `tests/e2e/CLAUDE.md`.
 - Prefer strong types over strings (enums, newtypes)
 - Keep functions focused, extract helpers when logic is reused
 - Comments for non-obvious logic only
+- **Prompt templates live in files, not Rust code**: Multi-line prompt strings (mission goals, system prompts, CodeAct preambles) go in `crates/ironclaw_engine/prompts/*.md` and are loaded via `include_str!()`. Never inline large prompt templates as Rust string constants — they're hard to read, review, and iterate on. Single-line format strings are fine inline.
 - **Logging levels matter for REPL/TUI**: `info!` and `warn!` output appears in the REPL and corrupts the terminal UI. Use `debug!` for internal diagnostics (trace analysis, reflection results, engine internals). Reserve `info!` for user-facing status that the REPL intentionally renders. Background tasks (reflection, trace analysis) must NEVER use `info!` — it breaks the interactive display.
 
 ## Architecture