feat: add face filter components and integration guide

- useFaceFilter composable: manages face filtering state and API calls
- FaceFilterPanel component: UI for filtering controls
- FaceCard component: text-only face display card
- Integration guide: step-by-step guide for integrating into PeopleView

Implements hybrid filtering mode with:
- Instant mode: client-side filtering (5-10ms)
- Backend mode: server-side complex filtering
- Hybrid mode: backend + instant filtering (AND)

Uses actual Core API endpoints:
- GET /file/{uuid}/faces
- POST /file/{uuid}/faces/filter
- GET /file/{uuid}/face/{faceId}/filter-report
- GET /file/{uuid}/filter-stats

Preferences stored in localStorage.

src-tauri/src/bin/gen_password.rs

@@ -1,12 +0,0 @@
-use argon2::{Algorithm, Argon2, Params, PasswordHasher, Version};
-use argon2::password_hash::{SaltString, rand_core::OsRng};
-
-fn main() {
-    let password = std::env::args().nth(1).unwrap_or_else(|| "demo123".to_string());
-    let salt = SaltString::generate(&mut OsRng);
-    let argon2 = Argon2::new(Algorithm::Argon2id, Version::V0x13, Params::default());
-    match argon2.hash_password(password.as_bytes(), &salt) {
-        Ok(hash) => println!("{}", hash),
-        Err(e) => eprintln!("Error: {}", e),
-    }
-}