chore(release): add MIT license, bundle metadata, and single NSIS target

Phase 1 of the 0.1.0 release prep:
- LICENSE (MIT) plus license fields in Cargo.toml, package.json, and bundle config
- tauri.conf.json: publisher/copyright/descriptions/homepage so the NSIS
  installer no longer derives 'jezz' from the identifier as manufacturer
- version: null in tauri.conf.json — Cargo.toml is now the version source
- bundle.targets narrowed from 'all' to nsis (updater-friendly, faster builds)
- track pnpm-workspace.yaml (esbuild build-script approval, needed by CI)

src-tauri/Cargo.toml

@@ -1,8 +1,9 @@
 [package]
 name = "phokus"
 version = "0.1.0"
-description = "A performant image gallery application"
+description = "Local-first desktop media library"
 authors = ["JezzWTF"]
+license = "MIT"
 edition = "2021"
 
 [lib]