Add transcript view modes (Summary / Normal / Verbose) to the VS Code extension to hide tool-call noise

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

In the VS Code extension, the conversation panel renders every tool call as its own full-size block — Read, Grep, Glob, each Playwright/MCP call (browser_navigate, browser_click, browser_take_screenshot, plus their "Ran code" / "Result" boxes), web fetches, and so on. On a long agentic session this produces a wall of low-signal noise that I have to scroll past to find the parts I actually care about: the reasoning, the todo updates, the edits, and the final answer.

The desktop app already solves this with transcript view modes (Summary / Normal / Verbose), where Summary collapses the tool churn. The VS Code extension has no equivalent — no view mode, no setting, and no way to collapse or hide tool-call blocks (only extended-thinking blocks collapse, via Ctrl+O). This is the single biggest readability gap between the extension and the desktop app.

Proposed Solution

Bring the desktop app's Summary / Normal / Verbose view modes to the VS Code extension, with a toggle in the panel and/or a setting.

At minimum, add a setting to hide or collapse-by-default specific tool-call block types in the transcript (e.g. Read, Grep, Glob, WebFetch, WebSearch, and all mcp__* tools), while keeping reasoning text, todo updates, Edit diffs, and Bash commands visible.

Alternative Solutions

• Click-to-collapse on individual tool blocks (like the existing thinking-block chevron), plus a collapse-all shortcut.
• A per-tool-type visibility config in settings.json.

Priority

High - Significantly impacts my daily workflow

Feature Category

Configuration and settings

Use Case Example

Writing/research/agentic sessions that make many Read and Playwright calls become very hard to follow in the VS Code panel — the meaningful output (an "Update Todos" block, a paragraph of reasoning, a final summary) is buried between dozens of "Ran Playwright code" / "Result" boxes.

Additional Context

Related but narrower: #72848 (hide/collapse subagent tool activity). This request covers all tool activity in the main conversation, not just subagents — the two could be unified under one "transcript verbosity / view mode" setting.