refactor: reduce CRAP scores in router/workflow/notification

- llm_router.go: Extract getStringFromMap, firstNonEmpty, paramResolver
  - buildCronSpec: 12 → 4 complexity
  - buildParameters: 9 → 5 complexity

- routing_workflow.go: Extract stateMachine, stateResult types
  - RoutingWorkflow: 11 → 6 complexity
  - Separate executeTask/executePass/executeFail

- notification.go: Extract checker interface pattern
  - DeploymentPreCheckActivity: 10 → 5 complexity
  - goCheckers() returns language-specific checkers

- Added 7 new test cases for helper functions
- Coverage: internal/routing 63.6% → 66.0%

action/notification.go

@@ -203,6 +203,70 @@ type DeploymentPreCheckOutput struct {
 	Warnings []string `json:"warnings"`
 }
 
+// checker defines a deployment check
+type checker struct {
+	name      string
+	types     []string // which checkTypes trigger this checker
+	isWarning bool     // if true, failure goes to warnings not failures
+	run       func(ctx context.Context, path string) (string, error)
+}
+
+// shouldRun checks if this checker should run for given checkType
+func (c *checker) shouldRun(checkType string) bool {
+	for _, t := range c.types {
+		if t == checkType {
+			return true
+		}
+	}
+	return false
+}
+
+// goCheckers returns checkers for Go projects
+func goCheckers() []*checker {
+	return []*checker{
+		{
+			name:  "build",
+			types: []string{"all", "build"},
+			run: func(ctx context.Context, path string) (string, error) {
+				cmd := exec.CommandContext(ctx, "go", "build", "./...")
+				cmd.Dir = path
+				out, err := cmd.CombinedOutput()
+				return string(out), err
+			},
+		},
+		{
+			name:  "test",
+			types: []string{"all", "test"},
+			run: func(ctx context.Context, path string) (string, error) {
+				cmd := exec.CommandContext(ctx, "go", "test", "-short", "./...")
+				cmd.Dir = path
+				out, err := cmd.CombinedOutput()
+				return string(out), err
+			},
+		},
+		{
+			name:      "lint",
+			types:     []string{"all", "lint"},
+			isWarning: true,
+			run: func(ctx context.Context, path string) (string, error) {
+				cmd := exec.CommandContext(ctx, "go", "vet", "./...")
+				cmd.Dir = path
+				out, err := cmd.CombinedOutput()
+				return string(out), err
+			},
+		},
+	}
+}
+
+// detectProjectCheckers returns checkers based on project type
+func detectProjectCheckers(path string) []*checker {
+	if _, err := os.Stat(fmt.Sprintf("%s/go.mod", path)); err == nil {
+		return goCheckers()
+	}
+	// Add more project types here (Node, Python, etc.)
+	return nil
+}
+
 // DeploymentPreCheckActivity validates deployment readiness
 func DeploymentPreCheckActivity(ctx context.Context, in DeploymentPreCheckInput) (DeploymentPreCheckOutput, error) {
 	logger := newActivityLogger(ctx)
@@ -226,38 +290,19 @@ func DeploymentPreCheckActivity(ctx context.Context, in DeploymentPreCheckInput)
 		return output, nil
 	}
 
-	// Check for Go project
-	isGo := false
-	if _, err := os.Stat(fmt.Sprintf("%s/go.mod", in.Path)); err == nil {
-		isGo = true
-	}
-
-	if isGo && (checkType == "all" || checkType == "build") {
-		// Try go build
-		cmd := exec.CommandContext(ctx, "go", "build", "./...")
-		cmd.Dir = in.Path
-		if buildOut, err := cmd.CombinedOutput(); err != nil {
-			output.Passed = false
-			output.Failures = append(output.Failures, fmt.Sprintf("build failed: %s", string(buildOut)))
+	// Run applicable checkers
+	for _, c := range detectProjectCheckers(in.Path) {
+		if !c.shouldRun(checkType) {
+			continue
 		}
-	}
-
-	if isGo && (checkType == "all" || checkType == "test") {
-		// Try go test
-		cmd := exec.CommandContext(ctx, "go", "test", "-short", "./...")
-		cmd.Dir = in.Path
-		if testOut, err := cmd.CombinedOutput(); err != nil {
-			output.Passed = false
-			output.Failures = append(output.Failures, fmt.Sprintf("tests failed: %s", string(testOut)))
-		}
-	}
-
-	if isGo && (checkType == "all" || checkType == "lint") {
-		// Try go vet
-		cmd := exec.CommandContext(ctx, "go", "vet", "./...")
-		cmd.Dir = in.Path
-		if vetOut, err := cmd.CombinedOutput(); err != nil {
-			output.Warnings = append(output.Warnings, fmt.Sprintf("vet issues: %s", string(vetOut)))
+		if out, err := c.run(ctx, in.Path); err != nil {
+			msg := fmt.Sprintf("%s failed: %s", c.name, out)
+			if c.isWarning {
+				output.Warnings = append(output.Warnings, msg)
+			} else {
+				output.Passed = false
+				output.Failures = append(output.Failures, msg)
+			}
 		}
 	}