feat(meeting): opt-in process-list reminder when a meeting app starts

Default off. When on, the layout polls detect_meeting_processes every 15s
with the user's app-name patterns. On a fresh match (edge-triggered — no
re-toast until the app goes away and comes back) we fire a reminder toast
that tells the user which meeting app appeared and their global hotkey. We
never start recording on this signal; the ideology rule says the user
decides. The signal is a single channel: process list match only — no mic
activity heuristic, no calendar.

Backend adds kon_core::process_watch::{list_running_process_names,
match_meeting_patterns} over sysinfo, exposed to the frontend as the
detect_meeting_processes Tauri command.

Settings ships two new fields — meetingAutoCapture (bool) and
meetingAutoCaptureApps (string[]) — with a comma-separated input in the
Output section. Default app list is ["zoom", "teams"], user-editable.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/core/src/lib.rs

@@ -2,6 +2,7 @@ pub mod constants;
 pub mod error;
 pub mod hardware;
 pub mod model_registry;
+pub mod process_watch;
 pub mod providers;
 pub mod recommendation;
 pub mod types;

crates/core/src/process_watch.rs

@@ -0,0 +1,85 @@
+//! Lightweight meeting-process detection.
+//!
+//! Scope (per Jake's ideology note): single signal only — poll the process
+//! list and match user-editable patterns. No mic-activity heuristic, no
+//! calendar integration. If the user opts in, we surface a non-modal toast
+//! so they can decide to start recording. We never start recording
+//! ourselves from this signal.
+
+use sysinfo::{ProcessRefreshKind, ProcessesToUpdate, RefreshKind, System};
+
+/// Snapshot the current process list's executable/command names. Lowercased
+/// for case-insensitive pattern matching.
+pub fn list_running_process_names() -> Vec<String> {
+    let mut system = System::new_with_specifics(
+        RefreshKind::nothing().with_processes(ProcessRefreshKind::nothing()),
+    );
+    system.refresh_processes(ProcessesToUpdate::All, true);
+    system
+        .processes()
+        .values()
+        .map(|process| process.name().to_string_lossy().to_lowercase())
+        .collect()
+}
+
+/// Match a snapshot of process names against case-insensitive substring
+/// `patterns`. Returns the set of patterns that matched at least once, in
+/// input order, deduped. Empty / whitespace-only patterns are skipped so
+/// a stray blank entry in the user's list never matches everything.
+pub fn match_meeting_patterns(process_names: &[String], patterns: &[String]) -> Vec<String> {
+    let mut matches: Vec<String> = Vec::new();
+    for raw_pattern in patterns {
+        let needle = raw_pattern.trim().to_lowercase();
+        if needle.is_empty() {
+            continue;
+        }
+        if process_names.iter().any(|name| name.contains(&needle)) {
+            if !matches.iter().any(|existing| existing == &needle) {
+                matches.push(needle);
+            }
+        }
+    }
+    matches
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn matches_are_case_insensitive_substrings() {
+        let processes = vec![
+            "Zoom Meeting".to_lowercase(),
+            "firefox".to_lowercase(),
+            "Microsoft Teams".to_lowercase(),
+        ];
+        let patterns = vec!["ZOOM".into(), "teams".into(), "discord".into()];
+
+        let got = match_meeting_patterns(&processes, &patterns);
+
+        assert_eq!(got, vec!["zoom", "teams"]);
+    }
+
+    #[test]
+    fn empty_and_whitespace_patterns_are_ignored() {
+        let processes = vec!["anything".to_lowercase()];
+        let patterns = vec!["".into(), "   ".into()];
+
+        assert!(match_meeting_patterns(&processes, &patterns).is_empty());
+    }
+
+    #[test]
+    fn matches_are_deduped() {
+        let processes = vec!["zoomclient".into(), "zoomhelper".into()];
+        let patterns = vec!["zoom".into(), "zoom".into()];
+
+        assert_eq!(match_meeting_patterns(&processes, &patterns), vec!["zoom"]);
+    }
+
+    #[test]
+    fn list_running_returns_something_on_this_host() {
+        // Smoke check — this is the test host and always has running procs.
+        let names = list_running_process_names();
+        assert!(!names.is_empty(), "expected at least one running process");
+    }
+}