test(coverage): whoami enrichment/nil-db; usage_wall + deploys_audit DB-error arms

- whoami.Get: nil-db early return + tier/email enrichment success.
- usage_wall.GetWall: db_failed via faultdb.
- deploys_audit.List: db_failed via faultdb.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: mastermanas805

internal/handlers/small_handlers_final_test.go

@@ -0,0 +1,89 @@
+package handlers_test
+
+// small_handlers_final_test.go — FINAL coverage pass for small handler arms:
+//   - whoami.Get: nil-db early return + email-enrichment success.
+//   - usage_wall.GetWall: db_failed via faultdb.
+//   - deploys_audit.List: db_failed via faultdb.
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/gofiber/fiber/v2"
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"instant.dev/internal/handlers"
+	"instant.dev/internal/middleware"
+	"instant.dev/internal/testhelpers"
+)
+
+// whoami.Get with a nil DB → early return without enrichment (whoami.go:55).
+func TestWhoamiFinal_NilDB_EarlyReturn(t *testing.T) {
+	app := fiber.New()
+	app.Use(func(c *fiber.Ctx) error {
+		c.Locals(middleware.LocalKeyTeamID, uuid.NewString())
+		c.Locals(middleware.LocalKeyUserID, uuid.NewString())
+		return c.Next()
+	})
+	h := handlers.NewWhoamiHandler(nil)
+	app.Get("/whoami", h.Get)
+	resp, err := app.Test(httptest.NewRequest(http.MethodGet, "/whoami", nil), 5000)
+	require.NoError(t, err)
+	defer resp.Body.Close()
+	assert.Equal(t, http.StatusOK, resp.StatusCode)
+}
+
+// whoami.Get with a real team + user → tier + email enrichment (whoami.go:63,74).
+func TestWhoamiFinal_Enrichment(t *testing.T) {
+	db, clean := testhelpers.SetupTestDB(t)
+	defer clean()
+	teamID := testhelpers.MustCreateTeamDB(t, db, "pro")
+	email := testhelpers.UniqueEmail(t)
+	var userID string
+	require.NoError(t, db.QueryRow(
+		`INSERT INTO users (team_id, email) VALUES ($1::uuid, $2) RETURNING id::text`, teamID, email).Scan(&userID))
+
+	app := fiber.New()
+	app.Use(func(c *fiber.Ctx) error {
+		c.Locals(middleware.LocalKeyTeamID, teamID)
+		c.Locals(middleware.LocalKeyUserID, userID)
+		return c.Next()
+	})
+	h := handlers.NewWhoamiHandler(db)
+	app.Get("/whoami", h.Get)
+	resp, err := app.Test(httptest.NewRequest(http.MethodGet, "/whoami", nil), 5000)
+	require.NoError(t, err)
+	defer resp.Body.Close()
+	require.Equal(t, http.StatusOK, resp.StatusCode)
+	var m map[string]any
+	require.NoError(t, decodeJSON(resp, &m))
+	assert.Equal(t, "pro", m["tier"])
+	assert.Equal(t, email, m["email"])
+}
+
+// usage_wall.GetWall: the usage query errors → db_failed (usage_wall.go:118).
+// team-tier check(1) errors-or-misses, then the usage query(2) errors. Use a
+// non-team tier so the early-return is skipped; failAfter=1 makes the usage
+// query error.
+func TestUsageWallFinal_DBError_503(t *testing.T) {
+	seedDB, clean := testhelpers.SetupTestDB(t)
+	defer clean()
+	teamID := uuid.MustParse(testhelpers.MustCreateTeamDB(t, seedDB, "pro"))
+
+	app := newUsageWallApp(t, openFaultDB(t, 1), teamID)
+	resp, err := app.Test(httptest.NewRequest(http.MethodGet, "/api/v1/usage/wall", nil), 5000)
+	require.NoError(t, err)
+	defer resp.Body.Close()
+	require.Equal(t, http.StatusServiceUnavailable, resp.StatusCode)
+}
+
+// deploys_audit.List: the list query errors → db_failed (deploys_audit.go:121).
+func TestDeploysAuditFinal_DBError_503(t *testing.T) {
+	t.Setenv(middleware.AdminEmailsEnvVar, deploysAuditAdminEmail)
+	app := deploysAuditApp(t, openFaultDB(t, 0), deploysAuditAdminEmail)
+	status, _ := deploysAuditDoGET(t, app, "/api/v1/admin/deploys")
+	assert.Equal(t, http.StatusServiceUnavailable, status)
+}