feat(frontend): pretty-print JSON in tool call and param displays

[steamEngineer]

Summary

Tool call outputs and JSON object parameters in the chat UI are currently rendered as minified one-line JSON strings, which makes debugging and reading tool results unnecessarily difficult.

This is a small frontend-only change that pretty-prints JSON with 2-space indentation wherever the UI already uses JSON.stringify for display.

What does this fix/solve?

• Tool call output blocks show minified JSON blobs (e.g. {"status":"ok","items":[...]}) that are hard to scan
• Tool call argument rows display nested object values as compact JSON
• Request params (Plus menu) and model config params (Admin → Models) have the same readability problem

After the change, valid JSON is formatted with indentation; non-JSON text is left unchanged.

Proposed changes

Three files, ~20 lines total:

1. cptr/frontend/src/lib/components/chat/ToolCallCollapsible.svelte

   • Add a $derived formatter that JSON.parses tool output when possible, then JSON.stringify(value, null, 2)
   • Use formatted output in the <pre> block (keeps existing 10k char truncation)
   • Pretty-print object values in argument rows

2. cptr/frontend/src/lib/components/chat/PlusMenu.svelte

   • JSON.stringify(value, null, 2) for object param values

3. cptr/frontend/src/lib/components/Admin/Models.svelte

   • Same for model request-param display

No new dependencies. Falls back to raw string when output is not valid JSON.

Test plan

• Expand a tool call whose output is JSON → output is indented and readable
• Expand a tool call whose output is plain text → unchanged
• Tool call with nested object arguments → args are indented
• Plus menu request params with object values → indented
• Admin → Models request params → indented
• Large JSON output still truncates at 10k chars with "... (truncated)" message

Contributor note

I have a working patch on branch feat/pretty-json-debug but I am unable to open a pull request directly against this repository (no push/PR permissions from my fork). Happy to share the full diff or adjust based on maintainer feedback — please let me know the preferred contribution path.

Commit message used locally:

feat(frontend): pretty-print JSON in tool call and param displays

Tool outputs and JSON object params were shown as minified one-liners,
making debugging hard to read. Parse and format with 2-space indent where
valid JSON; fall back to raw text otherwise.

[steamEngineer]

Branch is now pushed to my fork — the push had been blocked by GitHub email privacy (GH007) because the commit used a private Gmail as committer; fixed with the noreply address.

Fork branch (single commit on upstream/main): https://github.com/steamEngineer/computer/tree/feat/pretty-json

Compare / patch: main...steamEngineer:computer:feat/pretty-json

Commit: c93c52b — 3 files, +16/−7 lines.

I still can't open a PR directly against this repo from my account; happy for a maintainer to cherry-pick or open the PR from the compare link above.