chore(fmt): repo-wide gofmt -w sweep — close drift surfaced by ci-pipeline-cleanup Phase 4

Mechanical reformat. The new 'gofmt drift' CI step (added in
ci-pipeline-cleanup Phase 4, commit 71b2245) surfaced 111 files
with accumulated gofmt drift across cmd/, internal/, and deploy/test/.

Each file's diff is gofmt-standard: whitespace adjustments, intra-
group import sorting (alphabetical by import path within blank-line-
separated groups), and struct-tag column alignment. No semantic
changes — verified via 'git diff --ignore-all-space' which shows only
the line-position deltas from import reordering.

The gate stays in place after this commit. Going forward it catches
gofmt drift at PR time.

internal/service/agent_group_test.go

@@ -12,16 +12,16 @@ import (
 
 // mockAgentGroupRepo is a test implementation of AgentGroupRepository
 type mockAgentGroupRepo struct {
-	groups             map[string]*domain.AgentGroup
-	members            map[string][]*domain.Agent
-	CreateErr          error
-	UpdateErr          error
-	DeleteErr          error
-	GetErr             error
-	ListErr            error
-	ListMembersErr     error
-	AddMemberErr       error
-	RemoveMemberErr    error
+	groups          map[string]*domain.AgentGroup
+	members         map[string][]*domain.Agent
+	CreateErr       error
+	UpdateErr       error
+	DeleteErr       error
+	GetErr          error
+	ListErr         error
+	ListMembersErr  error
+	AddMemberErr    error
+	RemoveMemberErr error
 }
 
 func newMockAgentGroupRepository() *mockAgentGroupRepo {