Enhance timer function tracking with invocation count and log storage

- Add `invocation_count` column to `timer_functions` table
- Change `logs` column in `timer_function_invocations` to JSONB type
- Create trigger function to automatically increment invocation count on new log entries

routes/timer.py

@@ -25,6 +25,7 @@ CREATE TABLE timer_functions (
     next_run          TIMESTAMPTZ,
     last_run          TIMESTAMPTZ,
     enabled           BOOLEAN NOT NULL DEFAULT TRUE,
+    invocation_count INT NOT NULL DEFAULT 0,
 
     -- Define the foreign key constraint
     CONSTRAINT fk_timer_functions_user
@@ -107,7 +108,7 @@ CREATE TABLE timer_function_invocations (
     timer_function_id INT NOT NULL,
     status TEXT,
     invocation_time TIMESTAMPTZ NOT NULL DEFAULT NOW(),
-    logs TEXT,
+    logs JSONB,
     version_number INT NOT NULL,
 
     CONSTRAINT fk_timer_function_invocations
@@ -116,6 +117,23 @@ CREATE TABLE timer_function_invocations (
         ON DELETE CASCADE
 );
 
+CREATE OR REPLACE FUNCTION fn_increment_invocation_count()
+RETURNS TRIGGER
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    UPDATE timer_functions
+       SET invocation_count = invocation_count + 1
+     WHERE id = NEW.timer_function_id;
+
+    RETURN NEW;
+END;
+$$;
+
+CREATE TRIGGER tr_increment_invocation_count
+AFTER INSERT ON timer_function_invocations
+FOR EACH ROW
+EXECUTE PROCEDURE fn_increment_invocation_count();
 '''
 
 DEFAULT_SCRIPT = """async (req) => {
@@ -439,4 +457,3 @@ def history(function_id):
         return render_block(environment, 'dashboard/timer_functions/history.html', 'page', **args)
     return render_template('dashboard/timer_functions/history.html', **args)
 
-