feat: bot API token management page

The account page pointed users at a "bot-token list" that didn't exist: there
was no GET endpoint, no UI route, and the client type lacked expiry. Add
GET /v1/auth/tokens (caller-scoped, token_hash never serialised), extend the
auth client with listTokens/expires_at and createToken expiry, and add a
/profile/tokens page to list, create (revealing the raw bearer once), and
revoke tokens. Link the account-page copy to it.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

backend/src/repo/api_token.rs

@@ -32,6 +32,23 @@ pub async fn create(
     Ok(row)
 }
 
+/// The caller's tokens, newest first. `token_hash` is `#[serde(skip)]` on the
+/// domain type, so returning the full row never leaks the secret.
+pub async fn list_for_user(pool: &PgPool, user_id: Uuid) -> AppResult<Vec<ApiToken>> {
+    let rows = sqlx::query_as::<_, ApiToken>(
+        r#"
+        SELECT id, user_id, name, token_hash, created_at, last_used_at, expires_at
+        FROM api_tokens
+        WHERE user_id = $1
+        ORDER BY created_at DESC
+        "#,
+    )
+    .bind(user_id)
+    .fetch_all(pool)
+    .await?;
+    Ok(rows)
+}
+
 pub async fn find_active(pool: &PgPool, token_hash: &[u8]) -> AppResult<Option<ApiToken>> {
     let row = sqlx::query_as::<_, ApiToken>(
         r#"