Add Whisper user settings to config

Introduce a new struct `WhisperUserSettings` to hold per-user
transcription settings. This allows users to customize Whisper
transcription for their specific needs directly in the `users.toml`
configuration file.

The changes include:
- Defining `WhisperUserSettings` with optional fields for `language`,
  `hotwords`, and `initial_prompt`.
- Integrating `WhisperUserSettings` into the `User` struct, with
  `#[serde(default)]` to ensure it defaults to
  `WhisperUserSettings::default()` if not present in the TOML.
- Adding new unit tests to verify that users can be parsed correctly
  with and without a `[user.whisper]` block.
- Updating existing tests in `auth_test.rs`, `upload_test.rs`, and
  `web_test.rs` to include the new `whisper` field, ensuring backward
  compatibility.

server/src/config.rs

@@ -3,6 +3,15 @@ use std::path::PathBuf;
 
 use serde::Deserialize;
 
+/// Per-user Whisper transcription settings from users.toml.
+/// All fields optional — missing `[user.whisper]` block yields defaults (None).
+#[derive(Debug, Default, Clone, Deserialize)]
+pub struct WhisperUserSettings {
+    pub language: Option<String>,
+    pub hotwords: Option<String>,
+    pub initial_prompt: Option<String>,
+}
+
 /// A single user entry from users.toml.
 #[derive(Debug, Deserialize)]
 pub struct User {
@@ -10,6 +19,8 @@ pub struct User {
     pub api_key: String,
     pub web_password: String,
     pub role: String,
+    #[serde(default)]
+    pub whisper: WhisperUserSettings,
 }
 
 /// Wrapper for deserializing the [[user]] array from TOML.
@@ -158,9 +169,59 @@ mod tests {
             api_key: api_key.into(),
             web_password: String::new(),
             role: "doctor".into(),
+            whisper: WhisperUserSettings::default(),
         }
     }
 
+    #[test]
+    fn parses_user_without_whisper_block() {
+        let toml_str = r#"
+            [[user]]
+            slug = "a"
+            api_key = "k1"
+            web_password = ""
+            role = "doctor"
+        "#;
+        let parsed: UsersFile = toml::from_str(toml_str).unwrap();
+        let u = &parsed.user[0];
+        assert!(u.whisper.language.is_none());
+        assert!(u.whisper.hotwords.is_none());
+        assert!(u.whisper.initial_prompt.is_none());
+    }
+
+    #[test]
+    fn parses_user_with_full_whisper_block() {
+        let toml_str = r#"
+            [[user]]
+            slug = "a"
+            api_key = "k1"
+            web_password = ""
+            role = "doctor"
+              [user.whisper]
+              language = "de"
+              hotwords = "HOCM Valsalva"
+              initial_prompt = "Kardiologie"
+        "#;
+        let parsed: UsersFile = toml::from_str(toml_str).unwrap();
+        let w = &parsed.user[0].whisper;
+        assert_eq!(w.language.as_deref(), Some("de"));
+        assert_eq!(w.hotwords.as_deref(), Some("HOCM Valsalva"));
+        assert_eq!(w.initial_prompt.as_deref(), Some("Kardiologie"));
+    }
+
+    #[test]
+    fn accepts_admin_role() {
+        let toml_str = r#"
+            [[user]]
+            slug = "root"
+            api_key = "k1"
+            web_password = ""
+            role = "admin"
+        "#;
+        let parsed: UsersFile = toml::from_str(toml_str).unwrap();
+        assert_eq!(parsed.user[0].role, "admin");
+    }
+
     #[test]
     fn accepts_distinct_users() {
         let users = vec![u("a", "k1"), u("b", "k2")];

server/tests/auth_test.rs

@@ -19,6 +19,7 @@ fn test_config() -> Arc<Config> {
             api_key: "test-key-123".into(),
             web_password: "unused".into(),
             role: "doctor".into(),
+            whisper: Default::default(),
         }],
         api_keys: HashMap::from([("test-key-123".into(), "dr_test".into())]),
         retention_audio_days: 30,

server/tests/upload_test.rs

@@ -24,6 +24,7 @@ fn test_config() -> Arc<Config> {
             api_key: "test-key-123".into(),
             web_password: "unused".into(),
             role: "doctor".into(),
+            whisper: Default::default(),
         }],
         api_keys: HashMap::from([("test-key-123".into(), "dr_test".into())]),
         retention_audio_days: 30,

server/tests/web_test.rs

@@ -24,6 +24,7 @@ fn test_config() -> Arc<Config> {
             api_key: "test-key".into(),
             web_password: "unused".into(),
             role: "doctor".into(),
+            whisper: Default::default(),
         }],
         api_keys: HashMap::from([("test-key".into(), "dr_test".into())]),
         retention_audio_days: 30,