feat(usage): real-time stats refresh + fix codex sync panic on non-ASCII model names (#3027)

The usage dashboard previously only refreshed on app restart for users
who don't route through the cc-switch proxy. Two issues were involved:

1. The session-sync background task panicked when a Codex model name
   contained non-ASCII characters (e.g. `【官】glm-5.1`), because
   `normalize_codex_model` sliced `&name[name.len() - 11..]` without
   verifying char boundaries. Once the task panicked, no session logs
   were imported until the app was restarted (where startup-time
   `rollup_and_prune` happened to flush pending data).

2. Even with sync working, the dashboard only polled every 30s and
   skipped polling when the window was unfocused, so freshly-imported
   data was invisible until the next poll or window refocus.

Fixes
-----

* `normalize_codex_model`: guard the 11-byte ISO-date suffix slice with
  `is_char_boundary` + `is_ascii` checks. ASCII-only suffix means the
  date-stripping logic is correct, and non-ASCII names (which can never
  be valid date suffixes anyway) now bypass the slice safely.

* New `usage_events` module that emits `usage-log-recorded` to the
  frontend whenever `proxy_request_logs` actually gains a new row.
  Sources covered: proxy `log_request`, Claude/Codex/Gemini session
  sync, and startup `rollup_and_prune`. Notifications use a global
  `OnceLock<AppHandle>` so call sites that don't already hold an
  `AppHandle` (e.g. `UsageLogger`) can notify without signature churn.

* 200ms debounce in `notify_log_recorded` collapses bursts (a single
  Codex sync importing 3000+ entries triggers ~2 emits, not 3000) so
  the frontend's `invalidateQueries` is never spammed.

* Frontend `useUsageEventBridge` listens for the event and invalidates
  `usageKeys.all`. Hook is mounted only on `UsageDashboard`, so the
  listener is unsubscribed automatically when the user navigates away.

Verification
------------

* `cargo check` passes (existing 25 dead-code warnings in
  `commands/misc.rs` are pre-existing and unrelated).
* `tsc --noEmit` passes.
* Manually verified end-to-end: a Codex sync run that imported 3145
  entries produced 2 debounced emits, both logged as `emit
  usage-log-recorded 成功`, and the dashboard updated within ~200ms.

Behaviour notes
---------------

* `INSERT OR IGNORE` paths (Claude/Codex session sync) only notify when
  the row is actually inserted, so dedup-skipped writes don't trigger
  empty refreshes.
* Gemini's `INSERT … ON CONFLICT … DO UPDATE` path reuses the existing
  `conn.changes() > 0` check and only notifies when token counts truly
  changed.
* `rollup_and_prune` notifies once per pruning cycle (at most once per
  app start) so the dashboard reflects the new aggregate state.

Co-authored-by: in30mn1a <in30mn1a@users.noreply.github.com>

src-tauri/src/services/session_usage_codex.rs

@@ -75,9 +75,10 @@ fn normalize_codex_model(raw: &str) -> String {
     }
 
     // Step 3: 剥离 ISO 日期后缀 -YYYY-MM-DD（正好 11 字符）
-    if name.len() > 11 {
+    if name.len() > 11 && name.is_char_boundary(name.len() - 11) {
         let suffix = &name[name.len() - 11..];
-        if suffix.as_bytes()[0] == b'-'
+        if suffix.is_ascii()
+            && suffix.as_bytes()[0] == b'-'
             && suffix[1..5].chars().all(|c| c.is_ascii_digit())
             && suffix.as_bytes()[5] == b'-'
             && suffix[6..8].chars().all(|c| c.is_ascii_digit())
@@ -495,42 +496,47 @@ fn insert_codex_session_entry(
         ),
     };
 
-    conn.execute(
-        "INSERT OR IGNORE INTO proxy_request_logs (
+    let inserted_rows = conn
+        .execute(
+            "INSERT OR IGNORE INTO proxy_request_logs (
             request_id, provider_id, app_type, model, request_model,
             input_tokens, output_tokens, cache_read_tokens, cache_creation_tokens,
             input_cost_usd, output_cost_usd, cache_read_cost_usd, cache_creation_cost_usd, total_cost_usd,
             latency_ms, first_token_ms, status_code, error_message, session_id,
             provider_type, is_streaming, cost_multiplier, created_at, data_source
         ) VALUES (?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9, ?10, ?11, ?12, ?13, ?14, ?15, ?16, ?17, ?18, ?19, ?20, ?21, ?22, ?23, ?24)",
-        rusqlite::params![
-            request_id,
-            "_codex_session",    // provider_id
-            "codex",             // app_type
-            model,
-            model,               // request_model = model
-            delta.input,
-            delta.output,
-            delta.cached_input,
-            0i64,                // cache_creation_tokens: Codex 日志无此数据
-            input_cost,
-            output_cost,
-            cache_read_cost,
-            cache_creation_cost,
-            total_cost,
-            0i64,                // latency_ms
-            Option::<i64>::None, // first_token_ms
-            200i64,              // status_code
-            Option::<String>::None, // error_message
-            session_id.map(|s| s.to_string()),
-            Some("codex_session"), // provider_type
-            1i64,                // is_streaming
-            "1.0",               // cost_multiplier
-            created_at,
-            "codex_session",     // data_source
-        ],
-    )
-    .map_err(|e| AppError::Database(format!("插入 Codex 会话日志失败: {e}")))?;
+            rusqlite::params![
+                request_id,
+                "_codex_session",    // provider_id
+                "codex",             // app_type
+                model,
+                model,               // request_model = model
+                delta.input,
+                delta.output,
+                delta.cached_input,
+                0i64,                // cache_creation_tokens: Codex 日志无此数据
+                input_cost,
+                output_cost,
+                cache_read_cost,
+                cache_creation_cost,
+                total_cost,
+                0i64,                // latency_ms
+                Option::<i64>::None, // first_token_ms
+                200i64,              // status_code
+                Option::<String>::None, // error_message
+                session_id.map(|s| s.to_string()),
+                Some("codex_session"), // provider_type
+                1i64,                // is_streaming
+                "1.0",               // cost_multiplier
+                created_at,
+                "codex_session",     // data_source
+            ],
+        )
+        .map_err(|e| AppError::Database(format!("插入 Codex 会话日志失败: {e}")))?;
+
+    if inserted_rows > 0 {
+        crate::usage_events::notify_log_recorded();
+    }
 
     Ok(true)
 }