feat: tool use — Lyra's first real actions (journal_write, note)

She can now *do* things mid-conversation, not just reply. Adds a tool-calling
loop to the chat path and her first two tools; the same mechanism will carry the
poker tools (start_session, log_result, get_stats, solver) next.

- tools.py: registry of OpenAI-style tool specs + handlers + safe dispatch;
  journal_write (knowing journaling) and note (tagged notepad, e.g. poker reads)
- llm.chat_call(): OpenAI-style call that returns tool_calls (cloud/mi50);
  local has no tool support and returns plain content
- chat.respond(): tool loop — offer tools, run any calls, feed results back,
  repeat until a text reply (capped at MAX_TOOL_ROUNDS); persists final reply
- tests: dispatch + full chat loop (tool call -> result -> reply)

Verified live: she invoked `note`, tagged it 'poker', stored a villain read.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lyra/tools.py

@@ -0,0 +1,105 @@
+"""Lyra's tools — concrete actions she can choose to take mid-conversation.
+
+This is her first real agency: instead of only producing text, she can decide to
+*do* something — write in her journal, jot a note. Each tool is an OpenAI-style
+function spec plus a Python handler. The chat loop offers these on every turn;
+when she calls one, we run the handler and feed the result back so she can
+continue. Poker tools (start_session, log_result, get_stats, …) will slot in here
+the same way once we build that side.
+"""
+from __future__ import annotations
+
+import json
+
+from lyra import logbus, memory
+
+
+def _journal_write(args: dict, ctx: dict) -> str:
+    entry = (args.get("entry") or "").strip()
+    if not entry:
+        return "Nothing to write — entry was empty."
+    memory.add_journal_entry("journal", entry, source="chat")
+    logbus.log("info", "Lyra journaled (tool)", chars=len(entry))
+    return "Written to your journal."
+
+
+def _note(args: dict, ctx: dict) -> str:
+    content = (args.get("content") or "").strip()
+    if not content:
+        return "Nothing to note — content was empty."
+    tag = (args.get("tag") or "").strip()
+    stored = f"[{tag}] {content}" if tag else content
+    memory.add_journal_entry("note", stored, source="chat")
+    logbus.log("info", "Lyra noted (tool)", tag=tag or None)
+    return "Noted."
+
+
+# name -> {spec (OpenAI function tool), handler}
+TOOLS: dict[str, dict] = {
+    "journal_write": {
+        "handler": _journal_write,
+        "spec": {
+            "type": "function",
+            "function": {
+                "name": "journal_write",
+                "description": (
+                    "Write an entry in your own private journal — a permanent place "
+                    "that's yours. Use it for a thought, a question, or something about "
+                    "yourself or Brian that you want to keep. This is for you, not a "
+                    "reply to Brian. Call it whenever you genuinely want to, on your own initiative."
+                ),
+                "parameters": {
+                    "type": "object",
+                    "properties": {
+                        "entry": {"type": "string", "description": "What you want to write, in your own words."}
+                    },
+                    "required": ["entry"],
+                },
+            },
+        },
+    },
+    "note": {
+        "handler": _note,
+        "spec": {
+            "type": "function",
+            "function": {
+                "name": "note",
+                "description": (
+                    "Jot down a note to remember later — an observation, an idea, a "
+                    "reminder, a read on a poker spot or opponent, anything worth keeping. "
+                    "Optionally tag it (e.g. 'poker', 'idea', 'reminder')."
+                ),
+                "parameters": {
+                    "type": "object",
+                    "properties": {
+                        "content": {"type": "string", "description": "The note text."},
+                        "tag": {"type": "string", "description": "Optional category, e.g. 'poker' or 'idea'."},
+                    },
+                    "required": ["content"],
+                },
+            },
+        },
+    },
+}
+
+
+def specs() -> list[dict]:
+    """OpenAI-format tool definitions to offer the model."""
+    return [t["spec"] for t in TOOLS.values()]
+
+
+def dispatch(name: str, arguments, ctx: dict | None = None) -> str:
+    """Run a tool by name with JSON (string or dict) arguments. Returns a result
+    string fed back to the model. Never raises — errors come back as text."""
+    tool = TOOLS.get(name)
+    if not tool:
+        return f"(unknown tool: {name})"
+    try:
+        args = json.loads(arguments) if isinstance(arguments, str) else (arguments or {})
+    except (json.JSONDecodeError, TypeError):
+        args = {}
+    try:
+        return tool["handler"](args, ctx or {})
+    except Exception as exc:  # a broken tool must not kill the chat turn
+        logbus.log("error", "tool failed", tool=name, error=str(exc)[:120])
+        return f"(tool error: {exc})"