feat: highlight search matches and document the working UI

README.md

@@ -5,6 +5,12 @@
 Local desktop search for Windows, macOS and Linux, under active development.
 Production readiness is tracked in [the roadmap](docs/ROADMAP.md).
 
+![searchi finding a supplier agreement and its matching passage](docs/screenshots/search-light.png)
+
+*The production UI searching real fixture files with Google EmbeddingGemma 2.
+Captured on Windows with CPU inference in the read-only local browser capture harness;
+native window chrome is omitted.*
+
 ## What works
 
 Search combines instant indexed filenames, SQLite FTS5 content retrieval, and
@@ -35,6 +41,38 @@ Windows VM tests use CPU only. Files, extracted text, metadata and embeddings
 stay local; treat the index as sensitive. Initial verified model provisioning
 requires approximately 865 MB of downloads. Search performs no remote inference.
 
+## See searchi working
+
+### A familiar dark theme
+
+![The same real document search in searchi's dark theme](docs/screenshots/search-dark.png)
+
+Light and dark themes follow the operating system preference. The selected
+result retains its source location and extracted passage. Matching query words
+are highlighted in results and previews. A small, collapsed **Why this result?**
+detail is available when you want the explanation.
+
+### Find a photo from what you remember
+
+![A natural-language search finding the mountain lake photo](docs/screenshots/media-search.png)
+
+Actual image pixels are indexed by the Google model. The selected photo is
+loaded from the indexed fixture file for preview.
+
+### Understand where the time goes
+
+![searchi's detailed performance panel showing real search and inference timings](docs/screenshots/performance-details.png)
+
+Normal searches show a compact timing summary. Optional performance details
+break down the real request into measured stages, including worker inference,
+retrieval, filtering and ranking.
+
+The [capture workflow](tools/desktop-capture/README.md) and
+[capture manifest](docs/screenshots/capture-manifest.json) record the queries,
+runtime, measured responses and image hashes. The photo sources and licenses
+are listed in [the media fixture documentation](fixtures/media/README.md).
+These browser captures supplement the open native desktop QA gates.
+
 ## Copy-and-paste setup prompt
 
 ```text