chore: merge main into test/issue-711-hibernation-integration (gets scheduler #722 fix)

platform/internal/handlers/org.go

@@ -643,7 +643,14 @@ func (h *OrgHandler) createWorkspaceTree(ws OrgWorkspace, parentID *string, defa
 			log.Printf("Org import: schedule '%s' on %s has empty prompt (neither prompt nor prompt_file set) — skipping insert", sched.Name, ws.Name)
 			continue
 		}
-		nextRun, _ := scheduler.ComputeNextRun(sched.CronExpr, tz, time.Now())
+		// #722: surface the error rather than silently using time.Time{} (zero)
+		// which lib/pq stores as 0001-01-01 and may confuse the fire query.
+		nextRun, nextRunErr := scheduler.ComputeNextRun(sched.CronExpr, tz, time.Now())
+		if nextRunErr != nil {
+			log.Printf("Org import: invalid cron expression for schedule '%s' on %s: %v — skipping insert",
+				sched.Name, ws.Name, nextRunErr)
+			continue
+		}
 		if _, err := db.DB.ExecContext(context.Background(), orgImportScheduleSQL,
 			id, sched.Name, sched.CronExpr, tz, prompt, enabled, nextRun); err != nil {
 			log.Printf("Org import: failed to upsert schedule '%s' for %s: %v", sched.Name, ws.Name, err)

platform/internal/handlers/org_test.go

@@ -3,8 +3,11 @@ package handlers
 import (
 	"strings"
 	"testing"
+	"time"
 
 	"gopkg.in/yaml.v3"
+
+	"github.com/Molecule-AI/molecule-monorepo/platform/internal/scheduler"
 )
 
 func TestOrgDefaults_InitialPrompt_YAMLParsing(t *testing.T) {
@@ -602,3 +605,48 @@ func TestPlugins_BackwardCompat(t *testing.T) {
 		t.Fatalf("got %v, want %v", got, want)
 	}
 }
+
+// ── TestOrgImport_ScheduleComputeError (#722 Bug 2) ───────────────────────────
+//
+// The org importer previously used `nextRun, _ := scheduler.ComputeNextRun(...)`,
+// discarding the error and passing time.Time{} (zero value) to the INSERT.
+// After fix #722 it surfaces the error and skips the INSERT via `continue`.
+//
+// This test verifies that the inputs an org.yaml schedule can supply (bad cron
+// expression, invalid timezone) DO cause ComputeNextRun to return a non-nil
+// error — confirming that the fix is meaningful and the skip path is reachable.
+
+func TestOrgImport_ScheduleComputeError(t *testing.T) {
+	now := time.Now()
+	cases := []struct {
+		name     string
+		cronExpr string
+		tz       string
+	}{
+		{
+			name:     "invalid cron expression",
+			cronExpr: "not-a-cron-expr",
+			tz:       "UTC",
+		},
+		{
+			name:     "invalid timezone",
+			cronExpr: "0 9 * * 1",
+			tz:       "Not/A/Valid/Timezone",
+		},
+		{
+			name:     "both invalid",
+			cronExpr: "every monday",
+			tz:       "Moon/Far_Side",
+		},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			_, err := scheduler.ComputeNextRun(tc.cronExpr, tc.tz, now)
+			if err == nil {
+				t.Errorf("ComputeNextRun(%q, %q) returned nil error — "+
+					"org importer would silently insert zero next_run_at; #722 fix requires non-nil",
+					tc.cronExpr, tc.tz)
+			}
+		})
+	}
+}

platform/internal/middleware/wsauth_middleware.go

@@ -1,6 +1,7 @@
 package middleware
 
 import (
+	"crypto/subtle"
 	"database/sql"
 	"log"
 	"net/http"
@@ -64,20 +65,31 @@ func WorkspaceAuth(database *sql.DB) gin.HandlerFunc {
 // AdminAuth returns a Gin middleware for global/admin routes (e.g.
 // /settings/secrets, /admin/secrets) that have no per-workspace scope.
 //
-// Same lazy-bootstrap contract as WorkspaceAuth: if no live token exists
-// anywhere on the platform (fresh install / pre-Phase-30 upgrade), requests
-// are let through so existing deployments keep working. Once any workspace
-// has a live token every request to these routes MUST present a valid bearer
-// token — no Origin-based bypass. (#623)
+// # Credential tier (evaluated in order)
 //
-// Any valid workspace bearer token is accepted — the route is not scoped to
-// a specific workspace so we only verify the token is live and unrevoked.
+//  1. Lazy-bootstrap fail-open: if no live workspace token exists anywhere on
+//     the platform (fresh install / pre-Phase-30 upgrade), every request passes
+//     through so existing deployments keep working.
+//
+//  2. ADMIN_TOKEN env var (recommended, closes #684): when set, the bearer
+//     MUST equal this value exactly (constant-time comparison). Workspace
+//     bearer tokens are intentionally rejected even if valid — a compromised
+//     workspace agent must not be able to read global secrets, steal GitHub App
+//     installation tokens, or enumerate pending approvals across the platform.
+//     Set ADMIN_TOKEN to a strong random secret (e.g. openssl rand -base64 32).
+//
+//  3. Fallback — workspace token (deprecated, backward-compat): when
+//     ADMIN_TOKEN is not set and workspace tokens do exist globally, any valid
+//     workspace bearer token is still accepted. This preserves existing
+//     behaviour for deployments that have not yet configured ADMIN_TOKEN, but
+//     it leaves the blast-radius isolation gap described in #684 open. Set
+//     ADMIN_TOKEN to eliminate this fallback.
 //
 // NOTE: canvasOriginAllowed / isSameOriginCanvas are intentionally NOT called
 // here.  The Origin header is trivially forgeable by any container on the
 // Docker network; using it as an auth bypass would let an attacker reach
 // /settings/secrets, /bundles/import, /events, etc. without a bearer token.
-// Those short-circuits belong ONLY in CanvasOrBearer (cosmetic routes).
+// Those short-circuits belong ONLY in CanvasOrBearer (cosmetic routes). (#623)
 func AdminAuth(database *sql.DB) gin.HandlerFunc {
 	return func(c *gin.Context) {
 		ctx := c.Request.Context()
@@ -88,18 +100,34 @@ func AdminAuth(database *sql.DB) gin.HandlerFunc {
 			c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{"error": "auth check failed"})
 			return
 		}
-		if hasLive {
-			// Bearer token is the ONLY accepted credential for admin routes.
-			tok := wsauth.BearerTokenFromHeader(c.GetHeader("Authorization"))
-			if tok != "" {
-				if err := wsauth.ValidateAnyToken(ctx, database, tok); err != nil {
-					c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "invalid admin auth token"})
-					return
-				}
-				c.Next()
+		if !hasLive {
+			// Tier 1: fail-open on fresh install / pre-Phase-30 upgrade.
+			c.Next()
+			return
+		}
+
+		// Bearer token is the ONLY accepted credential for admin routes.
+		tok := wsauth.BearerTokenFromHeader(c.GetHeader("Authorization"))
+		if tok == "" {
+			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "admin auth required"})
+			return
+		}
+
+		// Tier 2 (#684 fix): dedicated ADMIN_TOKEN — workspace bearer tokens
+		// must not grant access to admin routes.
+		if adminSecret := os.Getenv("ADMIN_TOKEN"); adminSecret != "" {
+			if subtle.ConstantTimeCompare([]byte(tok), []byte(adminSecret)) != 1 {
+				c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "invalid admin auth token"})
 				return
 			}
-			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "admin auth required"})
+			c.Next()
+			return
+		}
+
+		// Tier 3 (deprecated): ADMIN_TOKEN not configured — fall back to any
+		// valid workspace token. Operators should set ADMIN_TOKEN to close #684.
+		if err := wsauth.ValidateAnyToken(ctx, database, tok); err != nil {
+			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "invalid admin auth token"})
 			return
 		}
 		c.Next()

platform/internal/middleware/wsauth_middleware_test.go

@@ -940,3 +940,233 @@ func TestAdminAuth_623_ValidBearer_WithOrigin_Passes(t *testing.T) {
 		t.Errorf("unmet sqlmock expectations: %v", err)
 	}
 }
+
+// ── Issue #684 — AdminAuth accepts any workspace bearer as admin credential ──
+//
+// Root cause: AdminAuth called ValidateAnyToken which matched any live
+// workspace token.  A compromised workspace agent could present its own bearer
+// and reach /admin/github-installation-token, /approvals/pending, etc.
+//
+// Fix: when ADMIN_TOKEN env var is set the middleware verifies the bearer
+// against that secret exclusively (constant-time).  Workspace tokens are
+// rejected even if valid.  When ADMIN_TOKEN is not set the old behaviour is
+// preserved for backward-compat (deprecated fallback, tier 3).
+
+// TestAdminAuth_684_AdminTokenSet_WorkspaceTokenRejected — the primary
+// regression test: when ADMIN_TOKEN is configured, a valid workspace bearer
+// token MUST be rejected with 401 on admin routes (#684).
+func TestAdminAuth_684_AdminTokenSet_WorkspaceTokenRejected(t *testing.T) {
+	mockDB, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("sqlmock.New: %v", err)
+	}
+	defer mockDB.Close()
+
+	t.Setenv("ADMIN_TOKEN", "super-secret-admin-token-xyz")
+
+	// Platform has live workspace tokens — AdminAuth is active.
+	mock.ExpectQuery(hasAnyLiveTokenGlobalQuery).
+		WillReturnRows(sqlmock.NewRows([]string{"count"}).AddRow(1))
+
+	// ValidateAnyToken must NOT be called — workspace tokens must be rejected
+	// before any DB lookup when ADMIN_TOKEN is set.
+
+	r := gin.New()
+	r.GET("/admin/github-installation-token", AdminAuth(mockDB), func(c *gin.Context) {
+		c.JSON(http.StatusOK, gin.H{"token": "ghp_live_token"})
+	})
+
+	w := httptest.NewRecorder()
+	// #684 attack: compromised workspace agent sends its own bearer.
+	req, _ := http.NewRequest(http.MethodGet, "/admin/github-installation-token", nil)
+	req.Header.Set("Authorization", "Bearer some-valid-workspace-bearer-token")
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusUnauthorized {
+		t.Errorf("#684 workspace token w/ ADMIN_TOKEN set: expected 401, got %d: %s",
+			w.Code, w.Body.String())
+	}
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("unmet sqlmock expectations: %v", err)
+	}
+}
+
+// TestAdminAuth_684_AdminTokenSet_CorrectAdminTokenAccepted — when ADMIN_TOKEN
+// is set, presenting the exact ADMIN_TOKEN value must grant access (200).
+func TestAdminAuth_684_AdminTokenSet_CorrectAdminTokenAccepted(t *testing.T) {
+	mockDB, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("sqlmock.New: %v", err)
+	}
+	defer mockDB.Close()
+
+	const adminSecret = "super-secret-admin-token-xyz"
+	t.Setenv("ADMIN_TOKEN", adminSecret)
+
+	mock.ExpectQuery(hasAnyLiveTokenGlobalQuery).
+		WillReturnRows(sqlmock.NewRows([]string{"count"}).AddRow(1))
+
+	// No DB token lookup — ADMIN_TOKEN check is env-only, no DB round-trip.
+
+	r := gin.New()
+	r.GET("/admin/github-installation-token", AdminAuth(mockDB), func(c *gin.Context) {
+		c.JSON(http.StatusOK, gin.H{"token": "ghp_live_token"})
+	})
+
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodGet, "/admin/github-installation-token", nil)
+	req.Header.Set("Authorization", "Bearer "+adminSecret)
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Errorf("#684 correct ADMIN_TOKEN: expected 200, got %d: %s", w.Code, w.Body.String())
+	}
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("unmet sqlmock expectations: %v", err)
+	}
+}
+
+// TestAdminAuth_684_AdminTokenSet_WrongAdminToken_Returns401 — when ADMIN_TOKEN
+// is set, presenting a different value must return 401.
+func TestAdminAuth_684_AdminTokenSet_WrongAdminToken_Returns401(t *testing.T) {
+	mockDB, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("sqlmock.New: %v", err)
+	}
+	defer mockDB.Close()
+
+	t.Setenv("ADMIN_TOKEN", "correct-admin-secret")
+
+	mock.ExpectQuery(hasAnyLiveTokenGlobalQuery).
+		WillReturnRows(sqlmock.NewRows([]string{"count"}).AddRow(1))
+
+	r := gin.New()
+	r.GET("/admin/liveness", AdminAuth(mockDB), func(c *gin.Context) {
+		c.JSON(http.StatusOK, gin.H{"subsystems": gin.H{}})
+	})
+
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodGet, "/admin/liveness", nil)
+	req.Header.Set("Authorization", "Bearer wrong-admin-secret")
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusUnauthorized {
+		t.Errorf("#684 wrong ADMIN_TOKEN: expected 401, got %d: %s", w.Code, w.Body.String())
+	}
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("unmet sqlmock expectations: %v", err)
+	}
+}
+
+// TestAdminAuth_684_AdminTokenSet_NoBearer_Returns401 — when ADMIN_TOKEN is
+// set, a request with no bearer must still return 401.
+func TestAdminAuth_684_AdminTokenSet_NoBearer_Returns401(t *testing.T) {
+	mockDB, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("sqlmock.New: %v", err)
+	}
+	defer mockDB.Close()
+
+	t.Setenv("ADMIN_TOKEN", "correct-admin-secret")
+
+	mock.ExpectQuery(hasAnyLiveTokenGlobalQuery).
+		WillReturnRows(sqlmock.NewRows([]string{"count"}).AddRow(1))
+
+	r := gin.New()
+	r.GET("/approvals/pending", AdminAuth(mockDB), func(c *gin.Context) {
+		c.JSON(http.StatusOK, gin.H{"approvals": []interface{}{}})
+	})
+
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodGet, "/approvals/pending", nil)
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusUnauthorized {
+		t.Errorf("#684 no bearer w/ ADMIN_TOKEN set: expected 401, got %d: %s",
+			w.Code, w.Body.String())
+	}
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("unmet sqlmock expectations: %v", err)
+	}
+}
+
+// TestAdminAuth_684_AdminTokenNotSet_FallsBackToWorkspaceToken — when
+// ADMIN_TOKEN is NOT set, a valid workspace token is still accepted (deprecated
+// tier-3 fallback for backward compatibility).
+func TestAdminAuth_684_AdminTokenNotSet_FallsBackToWorkspaceToken(t *testing.T) {
+	mockDB, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("sqlmock.New: %v", err)
+	}
+	defer mockDB.Close()
+
+	// ADMIN_TOKEN explicitly unset — tier-3 fallback active.
+	t.Setenv("ADMIN_TOKEN", "")
+
+	workspaceToken := "any-live-workspace-token"
+	tokenHash := sha256.Sum256([]byte(workspaceToken))
+
+	mock.ExpectQuery(hasAnyLiveTokenGlobalQuery).
+		WillReturnRows(sqlmock.NewRows([]string{"count"}).AddRow(1))
+
+	mock.ExpectQuery(validateAnyTokenSelectQuery).
+		WithArgs(tokenHash[:]).
+		WillReturnRows(sqlmock.NewRows([]string{"id"}).AddRow("tok-ws-1"))
+
+	mock.ExpectExec(validateTokenUpdateQuery).
+		WithArgs("tok-ws-1").
+		WillReturnResult(sqlmock.NewResult(0, 1))
+
+	r := gin.New()
+	r.GET("/admin/secrets", AdminAuth(mockDB), func(c *gin.Context) {
+		c.JSON(http.StatusOK, gin.H{"ok": true})
+	})
+
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodGet, "/admin/secrets", nil)
+	req.Header.Set("Authorization", "Bearer "+workspaceToken)
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Errorf("#684 fallback (no ADMIN_TOKEN): expected 200, got %d: %s",
+			w.Code, w.Body.String())
+	}
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("unmet sqlmock expectations: %v", err)
+	}
+}
+
+// TestAdminAuth_684_FailOpen_AdminTokenSet_NoGlobalTokens — even when
+// ADMIN_TOKEN is set, a fresh install (no tokens globally) must still
+// fail-open (tier-1 contract unchanged).
+func TestAdminAuth_684_FailOpen_AdminTokenSet_NoGlobalTokens(t *testing.T) {
+	mockDB, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("sqlmock.New: %v", err)
+	}
+	defer mockDB.Close()
+
+	t.Setenv("ADMIN_TOKEN", "some-admin-secret")
+
+	// HasAnyLiveTokenGlobal returns 0 — fresh install.
+	mock.ExpectQuery(hasAnyLiveTokenGlobalQuery).
+		WillReturnRows(sqlmock.NewRows([]string{"count"}).AddRow(0))
+
+	r := gin.New()
+	r.GET("/admin/secrets", AdminAuth(mockDB), func(c *gin.Context) {
+		c.JSON(http.StatusOK, gin.H{"ok": true})
+	})
+
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodGet, "/admin/secrets", nil)
+	// No bearer — but fail-open should still pass.
+	r.ServeHTTP(w, req)
+
+	if w.Code != http.StatusOK {
+		t.Errorf("#684 fail-open w/ ADMIN_TOKEN set (no global tokens): expected 200, got %d: %s",
+			w.Code, w.Body.String())
+	}
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("unmet sqlmock expectations: %v", err)
+	}
+}

platform/internal/scheduler/scheduler.go

@@ -112,6 +112,11 @@ func (s *Scheduler) Start(ctx context.Context) {
 		s.mu.Unlock()
 	}
 
+	// #722 — startup repair: find any enabled schedule whose next_run_at was
+	// NULL'd by the pre-fix bug and recompute it now. Without this pass those
+	// schedules would never fire again even after the binary is updated.
+	s.repairNullNextRunAt(ctx)
+
 	// Heartbeat + initial lastTickAt so /admin/liveness and Healthy() both
 	// pass during the first 30s interval after startup.
 	supervised.Heartbeat("scheduler")
@@ -279,12 +284,19 @@ func (s *Scheduler) fireSchedule(ctx context.Context, sched scheduleRow) {
 	var nextRunPtr *time.Time
 	if nextErr == nil {
 		nextRunPtr = &nextRun
+	} else {
+		// #722: if ComputeNextRun fails, keep the existing next_run_at so the
+		// schedule is not silently removed from the fire query (NULL next_run_at
+		// is excluded by the tick WHERE clause). COALESCE($2, next_run_at) does
+		// this: when $2 is NULL the DB column value is preserved as-is.
+		log.Printf("Scheduler: ComputeNextRun error for '%s' (%s) — preserving existing next_run_at: %v",
+			sched.Name, sched.ID, nextErr)
 	}
 
 	_, err := db.DB.ExecContext(ctx, `
 		UPDATE workspace_schedules
 		SET last_run_at = now(),
-		    next_run_at = $2,
+		    next_run_at = COALESCE($2, next_run_at),
 		    run_count = run_count + 1,
 		    last_status = $3,
 		    last_error = $4,
@@ -334,6 +346,11 @@ func (s *Scheduler) recordSkipped(ctx context.Context, sched scheduleRow, active
 	var nextRunPtr *time.Time
 	if nextErr == nil {
 		nextRunPtr = &nextRun
+	} else {
+		// #722: same guard as in fireSchedule — preserve existing next_run_at
+		// rather than writing NULL when the cron expression cannot be parsed.
+		log.Printf("Scheduler: ComputeNextRun error in recordSkipped for '%s' (%s) — preserving existing next_run_at: %v",
+			sched.Name, sched.ID, nextErr)
 	}
 
 	// Advance next_run_at + bump run_count so the liveness view reflects
@@ -342,7 +359,7 @@ func (s *Scheduler) recordSkipped(ctx context.Context, sched scheduleRow, active
 	_, _ = db.DB.ExecContext(ctx, `
 		UPDATE workspace_schedules
 		SET last_run_at = now(),
-		    next_run_at = $2,
+		    next_run_at = COALESCE($2, next_run_at),
 		    run_count = run_count + 1,
 		    last_status = 'skipped',
 		    last_error = $3,
@@ -371,6 +388,60 @@ func (s *Scheduler) recordSkipped(ctx context.Context, sched scheduleRow, active
 	}
 }
 
+// repairNullNextRunAt is called once during Start() to recompute next_run_at
+// for any enabled schedule where it is NULL — a state left by the pre-#722 bug
+// where a ComputeNextRun error caused an UPDATE that wrote NULL.
+// Without this repair those schedules would never appear in the tick query
+// (which requires next_run_at IS NOT NULL) even after the binary is patched.
+func (s *Scheduler) repairNullNextRunAt(ctx context.Context) {
+	rows, err := db.DB.QueryContext(ctx, `
+		SELECT id, cron_expr, timezone
+		FROM workspace_schedules
+		WHERE enabled = true AND next_run_at IS NULL
+	`)
+	if err != nil {
+		log.Printf("Scheduler: startup repair query error: %v", err)
+		return
+	}
+	defer rows.Close()
+
+	type repairRow struct {
+		ID       string
+		CronExpr string
+		Timezone string
+	}
+
+	var repaired, failed int
+	for rows.Next() {
+		var r repairRow
+		if err := rows.Scan(&r.ID, &r.CronExpr, &r.Timezone); err != nil {
+			log.Printf("Scheduler: startup repair scan error: %v", err)
+			continue
+		}
+		nextRun, err := ComputeNextRun(r.CronExpr, r.Timezone, time.Now())
+		if err != nil {
+			log.Printf("Scheduler: startup repair: cannot compute next_run_at for schedule %s (%s): %v — leaving NULL",
+				r.ID, r.CronExpr, err)
+			failed++
+			continue
+		}
+		if _, err := db.DB.ExecContext(ctx, `
+			UPDATE workspace_schedules SET next_run_at = $2, updated_at = now() WHERE id = $1
+		`, r.ID, nextRun); err != nil {
+			log.Printf("Scheduler: startup repair: update failed for schedule %s: %v", r.ID, err)
+			failed++
+		} else {
+			repaired++
+		}
+	}
+	if err := rows.Err(); err != nil {
+		log.Printf("Scheduler: startup repair rows error: %v", err)
+	}
+	if repaired > 0 || failed > 0 {
+		log.Printf("Scheduler: startup repair: %d schedule(s) repaired, %d skipped (bad cron/tz)", repaired, failed)
+	}
+}
+
 func truncate(s string, maxLen int) string {
 	if len(s) <= maxLen {
 		return s

platform/internal/scheduler/scheduler_test.go

@@ -2,6 +2,7 @@ package scheduler
 
 import (
 	"context"
+	"database/sql"
 	"testing"
 	"time"
 
@@ -10,6 +11,9 @@ import (
 	"github.com/Molecule-AI/molecule-monorepo/platform/internal/db"
 )
 
+// errDBDown is a sentinel error used by tests to simulate a DB connection failure.
+var errDBDown = sql.ErrConnDone
+
 // setupTestDB replaces the global db.DB with a sqlmock and returns the mock
 // handle. The real DB is restored (by closing the mock conn) via t.Cleanup.
 func setupTestDB(t *testing.T) sqlmock.Sqlmock {
@@ -237,6 +241,142 @@ func TestRecordSkipped_writesSkippedStatus(t *testing.T) {
 	}
 }
 
+// ── successProxy ─────────────────────────────────────────────────────────────
+
+// successProxy is a test double whose ProxyA2ARequest always returns HTTP 200
+// with no error, simulating a healthy A2A round-trip.
+type successProxy struct{}
+
+func (p *successProxy) ProxyA2ARequest(
+	_ context.Context, _ string, _ []byte, _ string, _ bool,
+) (int, []byte, error) {
+	return 200, []byte(`{"ok":true}`), nil
+}
+
+// ── TestFireSchedule_ComputeNextRunError (#722 Bug 1) ─────────────────────────
+//
+// When ComputeNextRun fails (bad cron expression), fireSchedule must NOT write
+// NULL to next_run_at — it must use COALESCE so the existing DB value is kept.
+// Proof: the UPDATE ExecContext must still be called (schedule not abandoned)
+// and sqlmock satisfies all expectations (no unexpected SQL).
+
+func TestFireSchedule_ComputeNextRunError(t *testing.T) {
+	mock := setupTestDB(t)
+
+	sched := scheduleRow{
+		ID:          "11111111-dead-beef-0000-000000000001",
+		WorkspaceID: "22222222-dead-beef-0000-000000000002",
+		Name:        "bad-cron-job",
+		CronExpr:    "not-a-valid-cron", // guaranteed to fail ComputeNextRun
+		Timezone:    "UTC",
+		Prompt:      "do something",
+	}
+
+	// active_tasks check → 0 (workspace is idle; proceed to fire)
+	mock.ExpectQuery(`SELECT COALESCE`).
+		WillReturnRows(sqlmock.NewRows([]string{"coalesce"}).AddRow(0))
+
+	// UPDATE must fire — COALESCE($2, next_run_at) keeps existing value when $2 is nil.
+	// AnyArg for $2 because it will be nil (ComputeNextRun failed).
+	mock.ExpectExec(`UPDATE workspace_schedules`).
+		WithArgs(sched.ID, sqlmock.AnyArg(), "ok", "").
+		WillReturnResult(sqlmock.NewResult(0, 1))
+
+	// activity_logs INSERT always fires
+	mock.ExpectExec(`INSERT INTO activity_logs`).
+		WithArgs(sched.WorkspaceID, sqlmock.AnyArg(), sqlmock.AnyArg(), "ok", "").
+		WillReturnResult(sqlmock.NewResult(0, 1))
+
+	s := New(&successProxy{}, nil)
+	s.fireSchedule(context.Background(), sched)
+
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("unmet DB expectations — schedule update was skipped or next_run_at not preserved: %v", err)
+	}
+}
+
+// ── TestRecordSkipped_ComputeNextRunError (#722 Bug 1 — skipped path) ─────────
+//
+// Same invariant as TestFireSchedule_ComputeNextRunError but for the
+// recordSkipped path: a bad cron expression must not NULL out next_run_at.
+
+func TestRecordSkipped_ComputeNextRunError(t *testing.T) {
+	mock := setupTestDB(t)
+
+	sched := scheduleRow{
+		ID:          "33333333-dead-beef-0000-000000000003",
+		WorkspaceID: "44444444-dead-beef-0000-000000000004",
+		Name:        "bad-cron-skip",
+		CronExpr:    "not-a-valid-cron",
+		Timezone:    "UTC",
+		Prompt:      "skipped task",
+	}
+
+	mock.ExpectExec(`UPDATE workspace_schedules`).
+		WithArgs(sched.ID, sqlmock.AnyArg(), sqlmock.AnyArg()).
+		WillReturnResult(sqlmock.NewResult(0, 1))
+	mock.ExpectExec(`INSERT INTO activity_logs`).
+		WithArgs(sched.WorkspaceID, sqlmock.AnyArg(), sqlmock.AnyArg(), sqlmock.AnyArg()).
+		WillReturnResult(sqlmock.NewResult(0, 1))
+
+	s := New(nil, nil)
+	s.recordSkipped(context.Background(), sched, 2)
+
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("unmet DB expectations: %v", err)
+	}
+}
+
+// ── TestRepairNullNextRunAt_RepairsRows (#722 Bug 3) ──────────────────────────
+//
+// repairNullNextRunAt must SELECT enabled schedules with NULL next_run_at,
+// compute the next fire time, and UPDATE each row.
+
+func TestRepairNullNextRunAt_RepairsRows(t *testing.T) {
+	mock := setupTestDB(t)
+
+	// Two schedules whose next_run_at is NULL and whose cron exprs are valid.
+	mock.ExpectQuery(`SELECT id, cron_expr, timezone`).
+		WillReturnRows(sqlmock.NewRows([]string{"id", "cron_expr", "timezone"}).
+			AddRow("sched-repair-01", "0 * * * *", "UTC").
+			AddRow("sched-repair-02", "30 9 * * 1", "America/New_York"))
+
+	// Expect one UPDATE per repaired row.
+	mock.ExpectExec(`UPDATE workspace_schedules`).
+		WithArgs("sched-repair-01", sqlmock.AnyArg()).
+		WillReturnResult(sqlmock.NewResult(0, 1))
+	mock.ExpectExec(`UPDATE workspace_schedules`).
+		WithArgs("sched-repair-02", sqlmock.AnyArg()).
+		WillReturnResult(sqlmock.NewResult(0, 1))
+
+	s := New(nil, nil)
+	s.repairNullNextRunAt(context.Background())
+
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("unmet DB expectations: %v", err)
+	}
+}
+
+// ── TestRepairNullNextRunAt_DBError_NoPanic (#722 Bug 3) ──────────────────────
+//
+// A DB error from the SELECT must be logged but must not panic — the scheduler
+// startup should proceed normally.
+
+func TestRepairNullNextRunAt_DBError_NoPanic(t *testing.T) {
+	mock := setupTestDB(t)
+
+	mock.ExpectQuery(`SELECT id, cron_expr, timezone`).
+		WillReturnError(errDBDown)
+
+	s := New(nil, nil)
+	// Must not panic:
+	s.repairNullNextRunAt(context.Background())
+
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Errorf("unmet DB expectations: %v", err)
+	}
+}
+
 // ── TestRecordSkipped_shortWorkspaceIDNoPanic ─────────────────────────────────
 // Guards against the short() regression: recordSkipped must not panic if
 // WorkspaceID is unexpectedly shorter than the 12-char prefix used in logs.