chore(ipc): bootstrap tauri-specta generator (1 command, no cutover)

Stand up the FE<->BE contract pipeline end to end with near-zero surface: a
tauri_specta::Builder collects one proven command (greet) and exports typed TS
bindings to src/generated/bindings.ts. The existing generate_handler! stays the
live invoke handler — no FE change yet.

Safety: the export runs only under #[cfg(debug_assertions)] (debug launch) and a
headless test, never in a release build, so a specta RC break can never block a
release cargo build; the committed bindings.ts is plain TypeScript for tsc. The
snapshot is committed (gitignore exception) so CI diffs catch contract drift.

Pinned deps: specta / tauri-specta =2.0.0-rc.25, specta-typescript =0.0.12 (the
latest mutually-consistent set; rc.21 + specta-typescript 0.0.9 no longer resolve).
Grow collect_commands! crate-by-crate next, starting with psysonic-library.

src-tauri/Cargo.lock

@@ -2,6 +2,12 @@
 # It is not intended for manual editing.
 version = 4
 
+[[package]]
+name = "Inflector"
+version = "0.11.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fe438c63458706e03479442743baae6c88256498e6431708f6dfc520a26515d3"
+
 [[package]]
 name = "adler2"
 version = "2.0.1"
@@ -4140,6 +4146,8 @@ dependencies = [
  "serde",
  "serde_json",
  "souvlaki",
+ "specta",
+ "specta-typescript",
  "symphonia",
  "symphonia-adapter-libopus",
  "sysinfo",
@@ -4154,6 +4162,7 @@ dependencies = [
  "tauri-plugin-store",
  "tauri-plugin-updater",
  "tauri-plugin-window-state",
+ "tauri-specta",
  "thread-priority",
  "tokio",
  "url",
@@ -5381,6 +5390,57 @@ dependencies = [
  "zvariant 3.15.2",
 ]
 
+[[package]]
+name = "specta"
+version = "2.0.0-rc.25"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "38f9a30cbcbb7011f1da7d73483983bf838af123883e45f2b36ed76328df9c50"
+dependencies = [
+ "paste",
+ "rustc_version",
+ "specta-macros",
+]
+
+[[package]]
+name = "specta-macros"
+version = "2.0.0-rc.25"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2ce14957ecc2897f1f848b8255b6531d13ddf49cbcf506b7c2c9fb1d005593bb"
+dependencies = [
+ "Inflector",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.117",
+]
+
+[[package]]
+name = "specta-serde"
+version = "0.0.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ee8a72b755ddb8949fd8f17c5db43f0e8a806ea587d9bc602ee3f73240c00029"
+dependencies = [
+ "specta",
+ "specta-macros",
+]
+
+[[package]]
+name = "specta-typescript"
+version = "0.0.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "639404ee95557f2f8b7e4cb773ffefd45304c7ab8ba21ac83b69051595e083c0"
+dependencies = [
+ "specta",
+]
+
+[[package]]
+name = "specta-util"
+version = "0.0.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "29b1fc02b446f7244a92924fe68c0555921209f1d342990cd1539e9138e69502"
+dependencies = [
+ "specta",
+]
+
 [[package]]
 name = "spin"
 version = "0.12.0"
@@ -5821,6 +5881,7 @@ dependencies = [
  "serde_json",
  "serde_repr",
  "serialize-to-javascript",
+ "specta",
  "swift-rs",
  "tauri-build",
  "tauri-macros",
@@ -6133,6 +6194,37 @@ dependencies = [
  "wry",
 ]
 
+[[package]]
+name = "tauri-specta"
+version = "2.0.0-rc.25"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ee080f36d2ac17ce2f3a82fb53f02d664e8345457de51b56dad3c394dacc41a2"
+dependencies = [
+ "heck 0.5.0",
+ "serde",
+ "serde_json",
+ "specta",
+ "specta-serde",
+ "specta-typescript",
+ "specta-util",
+ "tauri",
+ "tauri-specta-macros",
+ "thiserror 2.0.18",
+]
+
+[[package]]
+name = "tauri-specta-macros"
+version = "2.0.0-rc.25"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6a59dfdce06c98d8d211619bea5fdb39486d8a8c558e12b2d2ce255972320012"
+dependencies = [
+ "darling",
+ "heck 0.5.0",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.117",
+]
+
 [[package]]
 name = "tauri-utils"
 version = "2.9.2"