build(deps): gate CUDA behind default feature, add CPU build scripts

Applies the stashed 'deps and cpu mode' work: cuda was hardcoded on the
candle dependency lines, making the candle-cuda feature flag dead and any
non-CUDA build impossible. Now default = [candle-cuda] for the main dev
machine, with pnpm dev:app:cpu / build:app:cpu (--no-default-features) for
CPU-only machines and CI. Also trims unused deps (log, uuid, tokio-full,
chrono-serde). Verified: cargo check --locked --no-default-features passes.

package.json

@@ -9,6 +9,8 @@
     "build:vite": "tsc && vite build",
     "clean:app": "cd src-tauri && cargo clean",
     "dev:app": "tauri dev",
+    "dev:app:cpu": "tauri dev -- --no-default-features",
+    "build:app:cpu": "tauri build -- --no-default-features",
     "dev:vite": "vite",
     "preview": "vite preview",
     "tauri": "tauri"

src-tauri/Cargo.lock

@@ -4439,7 +4439,6 @@ dependencies = [
  "hnsw_rs",
  "image",
  "kamadak-exif",
- "log",
  "memmap2",
  "mozjpeg",
  "notify",
@@ -4461,7 +4460,6 @@ dependencies = [
  "tokenizers",
  "tokio",
  "ureq",
- "uuid",
  "walkdir",
  "xxhash-rust",
  "zip 4.6.1",
@@ -6537,25 +6535,11 @@ dependencies = [
  "bytes",
  "libc",
  "mio 1.2.0",
- "parking_lot",
  "pin-project-lite",
- "signal-hook-registry",
  "socket2",
- "tokio-macros",
  "windows-sys 0.61.2",
 ]
 
-[[package]]
-name = "tokio-macros"
-version = "2.7.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "385a6cb71ab9ab790c5fe8d67f1645e6c450a7ce006a33de03daa956cf70a496"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn 2.0.117",
-]
-
 [[package]]
 name = "tokio-native-tls"
 version = "0.3.1"

src-tauri/Cargo.toml

@@ -14,7 +14,9 @@ crate-type = ["staticlib", "cdylib", "rlib"]
 tauri-build = { version = "2", features = [] }
 
 [features]
-default = []
+# CUDA is on by default for the main dev machine; build with
+# `--no-default-features` (pnpm dev:app:cpu) on machines without the toolkit.
+default = ["candle-cuda"]
 candle-cuda = ["candle-core/cuda", "candle-nn/cuda", "candle-transformers/cuda"]
 
 [dependencies]
@@ -33,18 +35,16 @@ image = { version = "0.25", default-features = false, features = ["jpeg", "png",
 fast_image_resize = { version = "6.0.0", features = ["image"] }
 walkdir = "2"
 rayon = "1"
-tokio = { version = "1", features = ["full"] }
+tokio = { version = "1", features = ["rt-multi-thread"] }
-chrono = { version = "0.4", features = ["serde"] }
+chrono = "0.4"
-uuid = { version = "1", features = ["v4"] }
 anyhow = "1"
-log = "0.4"
 ffmpeg-sidecar = "2.5.0"
 xxhash-rust = { version = "0.8", features = ["xxh3"] }
 memmap2 = "0.9"
 sysinfo = "0.38.4"
-candle-core = { version = "0.10.2", features = ["cuda"] }
+candle-core = "0.10.2"
-candle-nn = { version = "0.10.2", features = ["cuda"] }
+candle-nn = "0.10.2"
-candle-transformers = { version = "0.10.2", features = ["cuda"] }
+candle-transformers = "0.10.2"
 hf-hub = { version = "0.5.0", default-features = false, features = ["ureq", "native-tls"] }
 tokenizers = "0.22.1"
 ort = { version = "2.0.0-rc.12", default-features = false, features = ["std", "ndarray", "download-binaries", "copy-dylibs", "load-dynamic", "directml", "api-24", "tls-native"] }