feat: tick prompt arg + fix name extraction learning verbs as names

Add optional prompt argument to `timmy tick` so custom journal
prompts can be passed from the CLI (seed_type="prompted").

Fix extract_user_name() learning verbs as names (e.g. "Serving").
Now requires the candidate word to start with a capital letter in
the original message, rejects common verb suffixes (-ing, -tion,
etc.), and deduplicates the naive regex in TimmyWithMemory to use
the fixed ConversationManager.extract_user_name() instead.

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

src/timmy/cli.py

@@ -23,13 +23,17 @@ _MODEL_SIZE_OPTION = typer.Option(
 
 
 @app.command()
-def tick():
-    """Run one autonomous thinking cycle (used by systemd timer)."""
+def tick(
+    prompt: str | None = typer.Argument(
+        None, help="Optional journal prompt for Timmy to reflect on"
+    ),
+):
+    """Run one thinking cycle. Pass a prompt to ask Timmy a specific question."""
     import asyncio
 
     from timmy.thinking import thinking_engine
 
-    thought = asyncio.run(thinking_engine.think_once())
+    thought = asyncio.run(thinking_engine.think_once(prompt=prompt))
     if thought:
         typer.echo(f"[{thought.seed_type}] {thought.content}")
     else: