Why

The spec browser uses raw Markdown rendering in dirty and refs diff modes — two unstructured markdown blobs side-by-side. This is inconsistent with the change > Specs tab, which uses SpecContentView (structured requirement/scenario rendering). The spec list in dirty/refs mode also shows only a changed badge with no indication of what changed at the requirement level, so maintainers must click into each spec to see the delta.

What Changes

Switch the spec browser's dirty and refs modes from raw Markdown to SpecContentView for before/after rendering. Add a compact semantic summary to spec list items in dirty/refs mode — requirement-level added/modified/removed counts computed from before/after content — so maintainers see "+2 req, ~1, -0" at a glance before clicking in.

Capabilities

New Capabilities

• spec-browser-structured-rendering: Structured rendering in spec browser diff modes and compact semantic summary in the spec list

Modified Capabilities

• spec-browser: Requirements modified to use structured rendering in diff modes and include semantic summary in list entries

Impact

• dashboard/dist/index.js — SpecsView uses SpecContentView instead of Markdown in dirty/refs modes; spec list items show semantic summary
• dashboard/plugin_api.py — _spec_browser computes semantic_summary (added/modified/removed counts) per spec in dirty and refs modes
• openspec/specs/spec-browser/spec.md — delta spec adding structured rendering and semantic summary requirements

Dependencies

• Requires semantic-spec-diff-tool — the shared _parse_spec and _semantic_spec_diff functions for computing summaries