fix: document Monty runtime limitations in CodeAct prompt, fix new-thread read-only

- Add "Runtime environment" section to codeact_preamble.md documenting
  Monty's restrictions: no stdlib imports, single imports only, no classes/
  with/match/del/yield, available builtins and modules, workarounds
- Add MONTY.md tracking current pin, all limitations, upgrade process,
  and changelog for future Monty updates
- Fix gateway createNewThread() not resetting read-only state — new
  threads now eagerly enable chat input instead of waiting for async
  loadThreads() callback

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

crates/ironclaw_engine/MONTY.md

@@ -0,0 +1,63 @@
+# Monty Integration
+
+Monty is the embedded Python interpreter used for Tier 1 (CodeAct) execution. It's a lightweight Rust-native Python implementation — not CPython — so it has a restricted feature set.
+
+**Source**: `git = "https://github.com/pydantic/monty.git", branch = "main"`
+**Pinned at**: `6053820` (2026-03-27, "Support max() kwargs/default")
+
+## Upgrade Process
+
+1. **Update the pin**: `cargo update -p monty`
+2. **Check for new features**: `cd ~/.cargo/git/checkouts/monty-*/*/` and `git log --oneline` since last pin
+3. **Update the preamble**: If a previously-unsupported feature now works, remove it from the "Runtime environment" section in `prompts/codeact_preamble.md`
+4. **Update this file**: Record the new pin and what changed
+5. **Run tests**: `cargo test -p ironclaw_engine`
+6. **Watch traces**: After deploying, check traces for new `NotImplementedError` patterns (self-improvement mission catches these)
+
+## Current Limitations (as of pin `6053820`)
+
+These are documented in `prompts/codeact_preamble.md` so the LLM avoids them:
+
+### Syntax not supported
+| Feature | Workaround |
+|---------|-----------|
+| `import a, b, c` (multi-module) | Use separate `import a` / `import b` statements |
+| `class Foo:` | Use functions and dicts |
+| `with` statements | Use try/finally or direct calls |
+| `match` statements | Use if/elif chains |
+| `del` statement | Reassign to None |
+| `yield` / `yield from` | Use lists and list comprehensions |
+| `*expr` (starred expressions) | Unpack explicitly |
+| `async` / `await` | Not available; tool calls suspend the VM automatically |
+| Type aliases (`type X = ...`) | Omit type annotations |
+| Template strings (t-strings) | Use f-strings |
+| Complex number literals | Use floats |
+| Exception groups (`try*/except*`) | Use regular try/except |
+
+### No standard library
+`import datetime`, `import csv`, `import json`, `import os`, `import io`, etc. all fail.
+
+Available built-in modules:
+- `math` — standard math functions
+- `re` — regex (basic)
+- `sys` — system info (limited)
+- `os.path` — path manipulation (limited)
+- `typing` — type hints (limited, for annotation only)
+
+### Available builtins
+`abs`, `all`, `any`, `bin`, `chr`, `divmod`, `enumerate`, `filter`, `getattr`, `hash`, `hex`, `id`, `isinstance`, `len`, `map`, `min`, `max`, `next`, `oct`, `ord`, `pow`, `print`, `repr`, `reversed`, `round`, `sorted`, `sum`, `type`, `zip`
+
+### Host-provided functions (always available)
+These are injected by the IronClaw executor, not by Monty:
+- `FINAL(answer)` / `FINAL_VAR(name)` — terminate with result
+- `llm_query(prompt, context)` — recursive LLM sub-call
+- `llm_query_batched(prompts)` — parallel sub-calls
+- `rlm_query(prompt)` — full sub-agent with tools
+- `globals()` / `locals()` — returns dict of known tool names
+- All tool functions (web_search, http, time, etc.)
+
+## Upgrade Changelog
+
+| Date | Pin | Notable changes |
+|------|-----|-----------------|
+| 2026-03-20 | `6053820` | Initial integration. max() kwargs support. |

crates/ironclaw_engine/prompts/codeact_preamble.md

@@ -40,3 +40,20 @@ You can write multiple code blocks across turns. Variables persist between block
 6. For large data, process it in chunks using llm_query() on subsets rather than loading everything into context.
 7. Outputs are truncated to 8000 chars — use variables to store large intermediate results.
 8. Include the actual content in your FINAL() answer, not just a count or summary. Users want to see the details.
+
+## Runtime environment
+
+The Python REPL runs in Monty, a lightweight embedded interpreter — not CPython. Key differences:
+
+- **No standard library modules**: `import datetime`, `import csv`, `import json`, `import os`, `import re` etc. will fail with `ModuleNotFoundError`. Use the provided tool functions instead (e.g. `time()` for dates, `http()` for fetching data, `json()` for parsing).
+- **Single imports only**: `import a, b, c` is not supported. Use separate statements: `import a` then `import b`.
+- **No classes**: `class Foo:` is not supported. Use functions and dicts instead.
+- **No `with` statements**: Use try/finally or just call functions directly.
+- **No `match` statements**: Use if/elif chains.
+- **No `del` statement**: Reassign to None instead.
+- **No `yield`/`yield from`**: Use lists and list comprehensions instead of generators.
+- **No `*expr` unpacking in assignments**: Unpack explicitly.
+- **Available builtins**: `abs`, `all`, `any`, `bin`, `chr`, `divmod`, `enumerate`, `filter`, `getattr`, `hash`, `hex`, `id`, `isinstance`, `len`, `map`, `min`, `max`, `next`, `oct`, `ord`, `pow`, `print`, `repr`, `reversed`, `round`, `sorted`, `sum`, `type`, `zip`.
+- **Available modules**: `math`, `re`, `sys`, `os.path`, `typing` (limited).
+- **String methods, list methods, dict methods**: All work normally.
+- For dates, use the `time()` tool. For CSV parsing, split strings manually. For HTTP, use `http()`. For JSON, use `json()` or work with dicts directly (tool results are already Python objects).

src/channels/web/static/app.js

@@ -2092,8 +2092,10 @@ function switchThread(threadId) {
 function createNewThread() {
   apiFetch('/api/chat/thread/new', { method: 'POST' }).then((data) => {
     currentThreadId = data.id || null;
+    currentThreadIsReadOnly = false;
     document.getElementById('chat-messages').innerHTML = '';
     showWelcomeCard();
+    enableChatInput();
     loadThreads();
   }).catch((err) => {
     showToast('Failed to create thread: ' + err.message, 'error');