llm templates listing should surface pinned model, schema and tools

Please describe. Thanks for the fast merge on the pipx link fix the other week. This one is a feature suggestion that came out of actually living with a growing llm templates collection.

llm templates shows the name and the prompt/system text, and that is it. Templates can now pin a lot more than that: model: (from --model at save time), schema_object: (from --schema), tools:/functions:, options:, and the extract: settings. None of that is visible from the listing, so answering a simple question like "which of my templates pin gpt-4o?" or "which ones need tools?" means running llm templates show on each one.

It gets more annoying after a plugin upgrade: the templates that pin a specific model are exactly the ones most likely to need attention, and there is no way to spot them from the list.

Describe the solution you'd like

A compact suffix of markers on each line of the llm templates output, for example:

cmd      : system: reply with macos terminal commands only, no extra information
dog      : prompt: invent a dog [schema]
report   : system: Write a QA report [model: gpt-4o] [tools: llm_time, search]

Markers only appear when the corresponding field is set, so existing listings look unchanged for simple prompt-only templates. The fields I would surface, in the order that seems most useful:

• [model: <model id>] when template.model is set
• [schema] when schema_object is set
• [tools: <n> or the names ] when tools is set
• maybe [fragments: <n>] for fragments, though that is more debatable

The template object is already fully loaded in templates_list() in llm/cli.py, so this is a pure display change, no new loading. The Template fields are all there in llm/templates.py.

Describe alternatives you've considered

• A --verbose flag for the extra info. I think the one-line markers are small enough to just always show, but a flag is fine too.
• A separate llm templates --json for scripting. Separate idea, could be its own issue.

I searched the tracker first: #44 added system prompts to this listing back in the day, but I did not find a prior discussion of surfacing model/schema/tools. Happy to open a PR for the marker version if you think the shape is right.