fix(tui): isolate OpenCode model config from profiles

internal/tui/model.go

@@ -158,6 +158,29 @@ func sanitizeKnownModelEffort(assignment model.ModelAssignment, sddModels map[st
 	return assignment
 }
 
+func (m Model) hasProfileAssignmentContext() bool {
+	return m.ProfileEditMode ||
+		m.ProfileDraft.Name != "" ||
+		m.ProfileDraft.OrchestratorModel.ProviderID != "" ||
+		m.ProfileDraft.OrchestratorModel.ModelID != "" ||
+		len(m.ProfileDraft.PhaseAssignments) > 0
+}
+
+func (m Model) withBaseOpenCodeModelAssignments() Model {
+	m.Selection.ModelAssignments = nil
+	settingsPath := opencode.DefaultSettingsPath()
+	if current, err := readCurrentAssignmentsFn(settingsPath); err == nil && len(current) > 0 {
+		m.Selection.ModelAssignments = sanitizeKnownModelEfforts(current, m.ModelPicker.SDDModels)
+	}
+	return m
+}
+
+func (m Model) withoutProfileAssignmentContext() Model {
+	m.ProfileEditMode = false
+	m.ProfileDraft = model.Profile{}
+	return m
+}
+
 // codexPhaseModelsFromCustomAssignments converts the TUI's CustomAssignments map
 // (phase → CodexCustomAssignment) to the state-layer map (phase → model id string)
 // used by Selection.CodexPhaseModelAssignments and state.InstallState.
@@ -1864,18 +1887,16 @@ func (m Model) confirmSelection() (tea.Model, tea.Cmd) {
 			} else {
 				m.ModelPicker = screens.ModelPickerState{}
 			}
-			// Pre-populate with existing assignments from opencode.json.
-			// Only when there are no in-session assignments yet — the nil guard
-			// ensures we don't overwrite changes the user already made this session.
-			if m.Selection.ModelAssignments == nil {
-				settingsPath := opencode.DefaultSettingsPath()
-				if current, err := readCurrentAssignmentsFn(settingsPath); err == nil && len(current) > 0 {
-					// Sanitize loaded assignments: clear any stale effort values for
-					// models that no longer report variants (e.g. provider refreshed
-					// their catalog since the user last synced). Without this, a stale
-					// effort would be preserved in the picker and re-injected on the
-					// next sync even if the model no longer supports that effort level.
-					m.Selection.ModelAssignments = sanitizeKnownModelEfforts(current, m.ModelPicker.SDDModels)
+			// Pre-populate with base OpenCode assignments from opencode.json when
+			// entering the standalone flow fresh, or after profile editing. Profile
+			// editing also uses Selection.ModelAssignments, so preserving that map here
+			// can leak a custom profile into the base/default OpenCode config screen.
+			// Non-profile in-session model config edits are still preserved.
+			profileAssignmentContext := m.hasProfileAssignmentContext()
+			if m.Selection.ModelAssignments == nil || profileAssignmentContext {
+				m = m.withBaseOpenCodeModelAssignments()
+				if profileAssignmentContext {
+					m = m.withoutProfileAssignmentContext()
 				}
 			}
 			m.setScreen(ScreenModelPicker)

internal/tui/model_test.go

@@ -2292,6 +2292,55 @@ func TestModelConfig_OpenCodePickerNavigation(t *testing.T) {
 	}
 }
 
+func TestModelConfigOpenCodeReloadsBaseAssignmentsAfterProfileEdit(t *testing.T) {
+	originalReadCurrentAssignmentsFn := readCurrentAssignmentsFn
+	t.Cleanup(func() { readCurrentAssignmentsFn = originalReadCurrentAssignmentsFn })
+
+	readCurrentAssignmentsFn = func(settingsPath string) (map[string]model.ModelAssignment, error) {
+		return map[string]model.ModelAssignment{
+			screens.SDDOrchestratorPhase: {ProviderID: "anthropic", ModelID: "claude-sonnet-4"},
+			"sdd-apply":                  {ProviderID: "openai", ModelID: "gpt-5"},
+		}, nil
+	}
+
+	m := NewModel(system.DetectionResult{}, "dev")
+	m.Screen = ScreenModelConfig
+	m.Cursor = 1
+	m.ProfileEditMode = true
+	m.ProfileDraft = model.Profile{
+		Name:              "work",
+		OrchestratorModel: model.ModelAssignment{ProviderID: "profile-provider", ModelID: "profile-orchestrator"},
+		PhaseAssignments: map[string]model.ModelAssignment{
+			"sdd-apply": {ProviderID: "profile-provider", ModelID: "profile-apply"},
+		},
+	}
+	m.Selection.ModelAssignments = map[string]model.ModelAssignment{
+		screens.SDDOrchestratorPhase: {ProviderID: "profile-provider", ModelID: "profile-orchestrator"},
+		"sdd-apply":                  {ProviderID: "profile-provider", ModelID: "profile-apply"},
+	}
+
+	updated, _ := m.Update(tea.KeyMsg{Type: tea.KeyEnter})
+	state := updated.(Model)
+
+	if state.ProfileEditMode {
+		t.Fatal("profile edit mode was not cleared")
+	}
+	if !reflect.DeepEqual(state.ProfileDraft, model.Profile{}) {
+		t.Fatalf("profile draft was not cleared: %+v", state.ProfileDraft)
+	}
+	if got := state.Selection.ModelAssignments[screens.SDDOrchestratorPhase].ProviderID; got != "anthropic" {
+		t.Fatalf("orchestrator provider = %q, want base OpenCode assignment", got)
+	}
+	if got := state.Selection.ModelAssignments["sdd-apply"].ModelID; got != "gpt-5" {
+		t.Fatalf("sdd-apply model = %q, want base OpenCode assignment", got)
+	}
+	for phase, assignment := range state.Selection.ModelAssignments {
+		if strings.HasPrefix(assignment.ProviderID, "profile-") || strings.HasPrefix(assignment.ModelID, "profile-") {
+			t.Fatalf("phase %q kept profile assignment: %+v", phase, assignment)
+		}
+	}
+}
+
 // TestModelConfig_BackNavigation verifies that selecting cursor 4 (Back) from
 // ScreenModelConfig returns to ScreenWelcome.
 // Index 3 is now "Configure Codex models"; Back moved to index 4.