feat: comprehensive INFO/WARN/ERROR logging across all controller modules

Add structured operational logging at INFO, WARN, and ERROR levels to
every controller module. Standardize custom prefixes ([GEO], [SCHED],
[SYNC]) to use [INFO/WARN/ERROR] [module] format. Fix misleveled logs
(WARN->ERROR for data loss scenarios, WARN->INFO for routine operations).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

controller/internal/stacks/manager.go

@@ -184,6 +184,8 @@ func (m *Manager) MigrateEncryption() {
 	}
 	if migrated > 0 {
 		m.logger.Printf("[INFO] Encrypted sensitive values in %d app.yaml file(s)", migrated)
+	} else {
+		m.logger.Printf("[INFO] [stacks] Encryption migration: no stacks needed migration")
 	}
 }
 
@@ -326,6 +328,7 @@ func (m *Manager) ScanStacks() error {
 	}
 	m.logger.Printf("[INFO] Scanned stacks: %d found (%d deployed, %d available)",
 		len(m.stacks), deployedCount, len(m.stacks)-deployedCount)
+	m.logger.Printf("[INFO] [stacks] ScanStacks complete: %d stacks found", len(m.stacks))
 	return m.refreshStatusLocked()
 }
 
@@ -370,6 +373,8 @@ func (m *Manager) refreshStatusLocked() error {
 		m.logger.Printf("[DEBUG] [stacks] refreshStatusLocked: docker ps returned %d containers across %d projects", totalContainers, len(projectContainers))
 	}
 
+	m.logger.Printf("[INFO] [stacks] Status refresh: %d containers across %d stacks", totalContainers, len(m.stacks))
+
 	for name, stack := range m.stacks {
 		containers, exists := projectContainers[name]
 		if !exists {
@@ -759,6 +764,7 @@ func (m *Manager) GetLogs(name string, lines int) (string, error) {
 		lines = 1000
 	}
 
+	m.logger.Printf("[INFO] [stacks] Fetching logs for stack %s (tail=%d)", name, lines)
 	m.logger.Printf("[DEBUG] Fetching logs for %s (tail %d)", name, lines)
 
 	dir := filepath.Dir(stack.ComposePath)