refactor: co-locate logging, manifest, network, privacy, prommetrics tests

Move unit tests from tests/unit/ to internal/ following Go conventions:
- tests/unit/logging/* -> internal/logging/* (logging tests)
- tests/unit/manifest/* -> internal/manifest/* (run_manifest, schema tests)
- tests/unit/network/* -> internal/network/* (retry, ssh_pool, ssh tests)
- tests/unit/privacy/* -> internal/privacy/* (pii tests)
- tests/unit/metrics/* -> internal/prommetrics/* (metrics tests)

Update import paths in test files to reflect new locations.

Note: metrics_test.go moved from tests/unit/metrics/ to internal/prommetrics/ to match the actual package name.

internal/logging/logging_test.go

@@ -1,4 +1,4 @@
-package tests
+package logging_test
 
 import (
 	"context"

internal/manifest/schema_test.go

@@ -1,4 +1,4 @@
-package manifest
+package manifest_test
 
 import (
 	"crypto/sha256"
@@ -19,7 +19,7 @@ func TestSchemaUnchanged(t *testing.T) {
 	// Get the project root (this test runs from internal/manifest/)
 	_, testFile, _, _ := runtime.Caller(0)
 	testDir := filepath.Dir(testFile)
-	schemaPath := filepath.Join(testDir, "..", "..", "..", "internal", "manifest", "schema.json")
+	schemaPath := filepath.Join(testDir, "schema.json")
 
 	// Load the committed schema
 	committedSchemaData, err := os.ReadFile(schemaPath)
@@ -65,7 +65,7 @@ func TestSchemaUnchanged(t *testing.T) {
 func TestSchemaValidatesExampleManifest(t *testing.T) {
 	_, testFile, _, _ := runtime.Caller(0)
 	testDir := filepath.Dir(testFile)
-	schemaPath := filepath.Join(testDir, "..", "..", "..", "internal", "manifest", "schema.json")
+	schemaPath := filepath.Join(testDir, "schema.json")
 
 	schemaLoader, err := loadSchemaFromFile(schemaPath)
 	if err != nil {
@@ -124,7 +124,7 @@ func TestSchemaValidatesExampleManifest(t *testing.T) {
 func TestSchemaRejectsInvalidManifest(t *testing.T) {
 	_, testFile, _, _ := runtime.Caller(0)
 	testDir := filepath.Dir(testFile)
-	schemaPath := filepath.Join(testDir, "..", "..", "..", "internal", "manifest", "schema.json")
+	schemaPath := filepath.Join(testDir, "schema.json")
 
 	schemaLoader, err := loadSchemaFromFile(schemaPath)
 	if err != nil {
@@ -228,7 +228,7 @@ func TestSchemaVersionMatchesConst(t *testing.T) {
 	_, testFile, _, _ := runtime.Caller(0)
 	testDir := filepath.Dir(testFile)
 	// Schema is in internal/manifest, not tests/unit/manifest
-	schemaPath := filepath.Join(testDir, "..", "..", "..", "internal", "manifest", "schema.json")
+	schemaPath := filepath.Join(testDir, "schema.json")
 
 	schemaData, err := os.ReadFile(schemaPath)
 	if err != nil {
@@ -274,7 +274,7 @@ func GenerateSchemaFromStructs() map[string]any {
 	// Since we have the schema committed, we just return it parsed
 	_, testFile, _, _ := runtime.Caller(0)
 	testDir := filepath.Dir(testFile)
-	schemaPath := filepath.Join(testDir, "..", "..", "..", "internal", "manifest", "schema.json")
+	schemaPath := filepath.Join(testDir, "schema.json")
 
 	data, err := os.ReadFile(schemaPath)
 	if err != nil {
@@ -302,7 +302,7 @@ func GenerateSchemaFromStructs() map[string]any {
 func GenerateSchemaJSON() []byte {
 	_, testFile, _, _ := runtime.Caller(0)
 	testDir := filepath.Dir(testFile)
-	schemaPath := filepath.Join(testDir, "..", "..", "..", "internal", "manifest", "schema.json")
+	schemaPath := filepath.Join(testDir, "schema.json")
 
 	data, err := os.ReadFile(schemaPath)
 	if err != nil {

internal/network/retry_test.go

@@ -1,4 +1,4 @@
-package tests
+package network_test
 
 import (
 	"context"

internal/network/ssh_pool_test.go

@@ -1,4 +1,4 @@
-package tests
+package network_test
 
 import (
 	"context"

internal/network/ssh_test.go

@@ -1,4 +1,4 @@
-package tests
+package network_test
 
 import (
 	"context"

internal/prommetrics/metrics_test.go

@@ -1,4 +1,4 @@
-package tests
+package prommetrics_test
 
 import (
 	"testing"