chore: stage all pending work — caption styling, media server, processing modal, docs, summaries

Includes:
- Extended caption styling (font, shadow, dimmed color, bg toggle)
- Media server, subtitle downloader, VTT parser, processing modal
- Waveform tiers, thumbnail/timeline improvements, transport controls
- Hybrid download model, dependency management, clip export enhancements
- 21 chat summaries, 2 implementation plans, 2 design specs

Co-authored-by: Cursor <cursoragent@cursor.com>

src-tauri/Cargo.toml

@@ -30,6 +30,8 @@ thiserror = "2.0.20"
 uuid = { version = "1.26.1", features = ["v4"] }
 tempfile = "3.27.0"
 dirs = "6.0.0"
+axum = "0.8"
+tower-http = { version = "0.6", features = ["fs", "cors"] }
 
 
 # Read the optimization guideline for more details: https://tauri.app/concept/size/#cargo-configuration