docs: update README/AGENTS for current codebase

- All references updated from fetch → akai-fetch
- AGENTS: document golangci-lint, extract.go replaces bash,
  remove findScript, update Electron binary name
- README: update roadmap, extraction tech stack
- mise.toml: add golangci-lint tool

README.md

@@ -12,7 +12,7 @@ Two interfaces:
 ```bash
 mise trust        # first time only
 mise install      # installs go 1.26, node 22
-mise run build    # → ./fetch
+mise run build    # → ./akai-fetch
 ```
 
 ### Toolchain check
@@ -32,14 +32,14 @@ mise run docker-up
 ```bash
 # CLI
 mise run build
-./fetch search --filter vocal
+./akai-fetch search --filter vocal
 
 # Web server (local)
 mise run serve
 # Open http://localhost:PORT (auto-assigned)
 
 # Web server (Docker / network-accessible)
-./fetch serve --host 0.0.0.0 -p 8080
+./akai-fetch serve --host 0.0.0.0 -p 8080
 # Open http://<host-ip>:8080
 
 # Electron (macOS)
@@ -60,14 +60,14 @@ akai-fetch serve [flags]           start HTTP server with web UI
 ## Architecture
 
 ```
-fetch serve (Go HTTP server, embedded web UI)
+akai-fetch serve (Go HTTP server, embedded web UI)
   ├── /api/search       archive.org search
   ├── /api/list         list ISO files in an item
   ├── /api/download     download ISOs with SSE progress
   ├── /api/extract      extract WAVs via akaiutil
   └── /api/progress     SSE download progress stream
 
-electron/               Electron wrapper (spawns fetch serve as sidecar)
+electron/               Electron wrapper (spawns akai-fetch serve as sidecar)
   ├── main.js           main process
   ├── preload.js        context bridge
   └── package.json      electron-builder config
@@ -87,7 +87,7 @@ third_party/akaiutil/   Vendored akaiutil 4.6.7 (C, GPLv2)
 | CLI server  | Go 1.26, stdlib    | 0 |
 | Web UI      | HTML/CSS/JS (vanilla) | 0 |
 | Electron    | Electron 33, electron-builder | Node deps |
-| Extraction  | akaiutil (C), bash | vendored C source |
+| Extraction  | akaiutil (C) via Go wrappers | vendored C source |
 
 Zero Go dependencies. The web UI uses no framework — vanilla JS, Web Audio API, Server-Sent Events.
 
@@ -99,6 +99,8 @@ See [open issues](https://git.notsosm.art/david/akai-utils/issues).
 |---|---------|--------|
 | — | Search, download, extract, pipeline (CLI) | done |
 | — | HTTP server + web UI + Electron shell | done |
+| — | WAV extraction re-implemented in Go | done |
+| — | MkdirAll error handling + parent dir creation for downloads | done |
 | — | Docker compose + mise toolchain + toolchain checks | done |
 | #1 | Disk Browser — browse AKAI filesystem in web UI | todo |
 | #2 | Disk Inspector — detailed disk metadata | todo |