various fixes on path validation

Units that cannot be executed are shown in red on both the Units and
Plans tabs.  Validation checks target existence/executability, shell
definition lookup, working directory existence, rectifier
existence/executability, and environment file existence.

The unit properties dialog applies live validation with GTK error
styling on each field and reports issues to the status bar as the
user edits.  Selecting a unit or task re-runs validation so the
status bar always reflects the selected item.

Also separates plan dirty state from unit editor dirty state so
editing unit properties no longer marks the plan as unsaved.

src/models/project.cpp

@@ -18,6 +18,7 @@
 
 #include "models/project.h"
 #include <set>
+#include <unistd.h>
 
 namespace grex {
 namespace fs = std::filesystem;
@@ -50,6 +51,82 @@ fs::path Project::resolved_shells_path() const {
     return root / sp;
 }
 
+// Extract the file path portion before any arguments
+static std::string extract_path(const std::string& s) {
+    auto pos = s.find(' ');
+    return pos == std::string::npos ? s : s.substr(0, pos);
+}
+
+bool Project::check_unit_valid(const Unit& u) {
+    namespace fs = std::filesystem;
+
+    if (u.target.empty()) {
+        report_status("Unit '" + u.name + "': target is not defined");
+        return false;
+    }
+    auto target_path = extract_path(u.target);
+    if (!fs::exists(target_path)) {
+        report_status("Unit '" + u.name + "': target does not exist: " + target_path);
+        return false;
+    }
+    if (access(target_path.c_str(), X_OK) != 0) {
+        report_status("Unit '" + u.name + "': target is not executable: " + target_path);
+        return false;
+    }
+
+    if (u.is_shell_command) {
+        bool found = false;
+        for (auto& s : all_shells()) {
+            if (s.name == u.shell_definition) { found = true; break; }
+        }
+        if (!found) {
+            report_status("Unit '" + u.name + "': shell definition not found: " + u.shell_definition);
+            return false;
+        }
+    }
+
+    if (u.set_working_directory) {
+        if (u.working_directory.empty()) {
+            report_status("Unit '" + u.name + "': working directory is not defined");
+            return false;
+        }
+        if (!fs::is_directory(u.working_directory)) {
+            report_status("Unit '" + u.name + "': working directory does not exist: " + u.working_directory);
+            return false;
+        }
+    }
+
+    if (u.rectify) {
+        if (u.rectifier.empty()) {
+            report_status("Unit '" + u.name + "': rectifier is not defined");
+            return false;
+        }
+        auto rectifier_path = extract_path(u.rectifier);
+        if (!fs::exists(rectifier_path)) {
+            report_status("Unit '" + u.name + "': rectifier does not exist: " + rectifier_path);
+            return false;
+        }
+        if (access(rectifier_path.c_str(), X_OK) != 0) {
+            report_status("Unit '" + u.name + "': rectifier is not executable: " + rectifier_path);
+            return false;
+        }
+    }
+
+    if (u.supply_environment) {
+        if (u.environment.empty()) {
+            report_status("Unit '" + u.name + "': environment file is not defined");
+            return false;
+        }
+        auto env_path = extract_path(u.environment);
+        if (!fs::exists(env_path)) {
+            report_status("Unit '" + u.name + "': environment file does not exist: " + env_path);
+            return false;
+        }
+    }
+
+    return true;
+}
+
 Unit* Project::find_unit(const std::string& unit_name) {
     for (auto& uf : unit_files) {
         auto* u = uf.find_unit(unit_name);

src/models/project.h

@@ -50,6 +50,7 @@ public:
     std::filesystem::path resolved_units_dir() const;
     std::filesystem::path resolved_shells_path() const;
 
+    bool check_unit_valid(const Unit& u);
     Unit* find_unit(const std::string& unit_name);
     UnitFile* find_unit_file(const std::string& unit_name);
     bool is_unit_name_taken(const std::string& name, const Unit* exclude = nullptr) const;

src/util/unit_properties_dialog.cpp

@@ -19,6 +19,7 @@
 #include "util/unit_properties_dialog.h"
 #include <cstdlib>
 #include <fstream>
+#include <unistd.h>
 
 namespace grex {
 
@@ -93,14 +94,17 @@ struct DialogState {
 };
 
 static void update_sensitivity(DialogState* s);
+static void validate_fields(DialogState* s);
 
 static gboolean dlg_switch_state_set_cb(GtkSwitch* sw, gboolean new_state, gpointer data) {
     auto* b = static_cast<DlgSwitchBinding*>(data);
     gtk_switch_set_state(sw, new_state);
     if (b->state) {
         *b->target = new_state;
-        if (!b->state->loading)
+        if (!b->state->loading) {
             update_sensitivity(b->state);
+            validate_fields(b->state);
+        }
     }
     return TRUE;
 }
@@ -361,6 +365,116 @@ static void update_sensitivity(DialogState* s) {
     show(active && s->working_copy.supply_environment, {s->label_environment, s->box_environment});
 }
 
+static std::string extract_path(const std::string& s) {
+    auto pos = s.find(' ');
+    return pos == std::string::npos ? s : s.substr(0, pos);
+}
+
+static void validate_fields(DialogState* s) {
+    if (s->loading) return;
+
+    auto& u = s->working_copy;
+    namespace fs = std::filesystem;
+
+    auto set_valid = [](GtkWidget* w, bool valid) {
+        if (valid)
+            gtk_widget_remove_css_class(w, "error");
+        else
+            gtk_widget_add_css_class(w, "error");
+    };
+
+    std::string error_msg;
+
+    // Target: must be defined, exist, and be executable
+    {
+        bool valid = true;
+        if (u.target.empty()) {
+            valid = false;
+            if (error_msg.empty()) error_msg = "Target is not defined";
+        } else {
+            auto tp = extract_path(u.target);
+            if (!fs::exists(tp)) {
+                valid = false;
+                if (error_msg.empty()) error_msg = "Target does not exist: " + tp;
+            } else if (access(tp.c_str(), X_OK) != 0) {
+                valid = false;
+                if (error_msg.empty()) error_msg = "Target is not executable: " + tp;
+            }
+        }
+        set_valid(s->entry_target, valid);
+    }
+
+    // Shell definition: if shell command, must reference a known shell
+    if (u.is_shell_command) {
+        bool valid = false;
+        for (auto& sh : *s->shells) {
+            if (sh.name == u.shell_definition) { valid = true; break; }
+        }
+        set_valid(s->dropdown_shell_def, valid);
+        if (!valid && error_msg.empty())
+            error_msg = "Shell definition not found: " + u.shell_definition;
+    } else {
+        set_valid(s->dropdown_shell_def, true);
+    }
+
+    // Working directory: must exist as a directory if enabled
+    if (u.set_working_directory) {
+        bool valid = true;
+        if (u.working_directory.empty()) {
+            valid = false;
+            if (error_msg.empty()) error_msg = "Working directory is not defined";
+        } else if (!fs::is_directory(u.working_directory)) {
+            valid = false;
+            if (error_msg.empty()) error_msg = "Working directory does not exist: " + u.working_directory;
+        }
+        set_valid(s->entry_workdir, valid);
+    } else {
+        set_valid(s->entry_workdir, true);
+    }
+
+    // Rectifier: must exist and be executable if rectification enabled
+    if (u.rectify) {
+        bool valid = true;
+        if (u.rectifier.empty()) {
+            valid = false;
+            if (error_msg.empty()) error_msg = "Rectifier is not defined";
+        } else {
+            auto rp = extract_path(u.rectifier);
+            if (!fs::exists(rp)) {
+                valid = false;
+                if (error_msg.empty()) error_msg = "Rectifier does not exist: " + rp;
+            } else if (access(rp.c_str(), X_OK) != 0) {
+                valid = false;
+                if (error_msg.empty()) error_msg = "Rectifier is not executable: " + rp;
+            }
+        }
+        set_valid(s->entry_rectifier, valid);
+    } else {
+        set_valid(s->entry_rectifier, true);
+    }
+
+    // Environment file: must exist if supply_environment active
+    if (u.supply_environment) {
+        bool valid = true;
+        if (u.environment.empty()) {
+            valid = false;
+            if (error_msg.empty()) error_msg = "Environment file is not defined";
+        } else {
+            auto ep = extract_path(u.environment);
+            if (!fs::exists(ep)) {
+                valid = false;
+                if (error_msg.empty()) error_msg = "Environment file does not exist: " + ep;
+            }
+        }
+        set_valid(s->entry_environment, valid);
+    } else {
+        set_valid(s->entry_environment, true);
+    }
+
+    if (!error_msg.empty())
+        s->project->report_status(error_msg);
+}
+
 static void populate_and_connect(DialogState* s) {
     auto& u = s->working_copy;
 
@@ -390,6 +504,7 @@ static void populate_and_connect(DialogState* s) {
     gtk_editable_set_text(GTK_EDITABLE(s->entry_environment), u.environment.c_str());
     update_sensitivity(s);
     s->loading = false;
+    validate_fields(s);
 
     // Entry bindings
     auto bind_entry = [s](GtkWidget* entry, std::string* target) {
@@ -398,6 +513,7 @@ static void populate_and_connect(DialogState* s) {
         g_signal_connect(entry, "changed", G_CALLBACK(+[](GtkEditable* e, gpointer d) {
             auto* eb = static_cast<DlgEntryBinding*>(d);
             *eb->target = gtk_editable_get_text(e);
+            validate_fields(eb->state);
         }), eb);
     };
     bind_entry(s->entry_name, &u.name);
@@ -430,6 +546,7 @@ static void populate_and_connect(DialogState* s) {
         auto idx = gtk_drop_down_get_selected(GTK_DROP_DOWN(obj));
         if (idx < s->shells->size())
             s->working_copy.shell_definition = (*s->shells)[idx].name;
+        validate_fields(s);
     }), s);
 }
 

src/views/main_window.cpp

@@ -225,16 +225,7 @@ void MainWindow::refresh_visible_page() {
 
     // Refresh the newly visible page
     if (visible == plan_view_->widget()) {
-        project_.load_all_units();
-        if (!project_.plans.empty()) {
-            auto& plan = project_.plans[0];
-            try {
-                plan = Plan::load(plan.filepath);
-            } catch (const std::exception& e) {
-                project_.report_status(std::string("Error reloading plan: ") + e.what());
-            }
-        }
-        plan_view_->refresh();
+        plan_view_->reload_plan_from_disk();
     } else if (visible == units_view_->widget()) {
         units_view_->refresh();
     } else if (visible == shells_view_->widget()) {

src/views/plan_view.cpp

@@ -135,11 +135,13 @@ PlanView::PlanView(Project& project, GrexConfig& grex_config)
     gtk_frame_set_child(GTK_FRAME(task_ctrl_frame_), task_ctrl_box);
     gtk_box_append(GTK_BOX(unit_editor_->content_box()), task_ctrl_frame_);
 
-    // Name change callback to refresh the task list row label
-    unit_editor_->set_name_changed_callback([](const std::string&, void* data) {
+    // Callback fired after any unit edit in the dialog
+    unit_editor_->set_unit_edited_callback([](const std::string&, bool name_changed, void* data) {
         auto* self = static_cast<PlanView*>(data);
+        if (name_changed) {
             self->plan_dirty_ = true;
             gtk_widget_add_css_class(self->btn_save_plan_, "suggested-action");
+        }
         if (self->current_task_idx_ >= 0)
             self->refresh_task_row(self->current_task_idx_);
     }, this);
@@ -167,7 +169,7 @@ PlanView::PlanView(Project& project, GrexConfig& grex_config)
 
     g_signal_connect(btn_refresh, "clicked", G_CALLBACK(+[](GtkButton*, gpointer d) {
         auto* self = static_cast<PlanView*>(d);
-        self->refresh();
+        self->reload_plan_from_disk();
     }), this);
 
     g_signal_connect(btn_delete_plan, "clicked", G_CALLBACK(on_delete_plan), this);
@@ -195,8 +197,17 @@ void PlanView::populate_task_list() {
 
     for (auto& task : plan->tasks) {
         auto* row = gtk_list_box_row_new();
-        auto text = std::string("\u25B6 ") + task.name;
-        auto* label = gtk_label_new(text.c_str());
+        auto* label = gtk_label_new(nullptr);
+        auto* escaped = g_markup_escape_text(task.name.c_str(), -1);
+        Unit* unit = project_.find_unit(task.name);
+        bool valid = unit && project_.check_unit_valid(*unit);
+        std::string markup;
+        if (valid)
+            markup = std::string("\u25B6 ") + escaped;
+        else
+            markup = std::string("<span foreground=\"red\">\u25B6 ") + escaped + "</span>";
+        g_free(escaped);
+        gtk_label_set_markup(GTK_LABEL(label), markup.c_str());
         gtk_label_set_xalign(GTK_LABEL(label), 0.0f);
         gtk_widget_set_margin_start(label, 8);
         gtk_widget_set_margin_end(label, 8);
@@ -217,8 +228,17 @@ void PlanView::refresh_task_row(int idx) {
 
     auto* label = gtk_list_box_row_get_child(GTK_LIST_BOX_ROW(row));
     if (GTK_IS_LABEL(label)) {
-        auto text = std::string("\u25B6 ") + plan->tasks[idx].name;
-        gtk_label_set_text(GTK_LABEL(label), text.c_str());
+        auto& task = plan->tasks[idx];
+        auto* escaped = g_markup_escape_text(task.name.c_str(), -1);
+        Unit* unit = project_.find_unit(task.name);
+        bool valid = unit && project_.check_unit_valid(*unit);
+        std::string markup;
+        if (valid)
+            markup = std::string("\u25B6 ") + escaped;
+        else
+            markup = std::string("<span foreground=\"red\">\u25B6 ") + escaped + "</span>";
+        g_free(escaped);
+        gtk_label_set_markup(GTK_LABEL(label), markup.c_str());
     }
 }
 
@@ -237,6 +257,10 @@ void PlanView::select_task(int idx) {
         project_.load_all_units();
 
     Unit* unit = project_.find_unit(task.name);
+    if (unit)
+        project_.check_unit_valid(*unit);
+    else
+        project_.report_status("Unit not found: " + task.name);
 
     unit_editor_->load(&task, unit);
     update_move_buttons();
@@ -552,23 +576,27 @@ void PlanView::update_move_buttons() {
     gtk_widget_set_sensitive(btn_move_down_, current_task_idx_ < count - 1);
 }
 
-void PlanView::refresh() {
-    // reload units if paths now resolve
-    project_.load_all_units();
-
-    // reload the plan from disk if one is loaded
+void PlanView::reload_plan_from_disk() {
     auto* plan = current_plan();
-    if (plan) {
+    if (!plan) return;
     try {
         *plan = Plan::load(plan->filepath);
         project_.report_status("Reloaded plan: " + plan->filepath.filename().string());
     } catch (const std::exception& e) {
         project_.report_status("Error reloading plan: " + std::string(e.what()));
     }
+    refresh();
+}
+
+void PlanView::refresh() {
+    // reload units if paths now resolve
+    project_.load_all_units();
+
+    auto* plan = current_plan();
+    if (plan)
         gtk_label_set_markup(GTK_LABEL(plan_label_), (std::string("<b>Plan:</b> ") + plan->filepath.filename().string()).c_str());
-    } else {
+    else
         gtk_label_set_markup(GTK_LABEL(plan_label_), "<b>Plan:</b> No plan loaded");
-    }
 
     populate_task_list();
     update_plan_buttons();
@@ -577,7 +605,7 @@ void PlanView::refresh() {
 }
 
 bool PlanView::is_dirty() const {
-    return plan_dirty_ || unit_editor_->is_dirty();
+    return plan_dirty_;
 }
 
 void PlanView::save_dirty() {

src/views/plan_view.h

@@ -30,6 +30,7 @@ public:
     PlanView(Project& project, GrexConfig& grex_config);
     GtkWidget* widget() { return root_; }
     void refresh();
+    void reload_plan_from_disk();
     bool is_dirty() const;
     void save_dirty();
     void revert_dirty();

src/views/shells_view.cpp

@@ -417,7 +417,8 @@ void ShellsView::on_delete_file(GtkButton*, gpointer data) {
     auto* self = static_cast<ShellsView*>(data);
     if (!self->selected_file_) return;
 
-    auto name = self->selected_file_->filepath.filename().string();
+    auto filepath = self->selected_file_->filepath;
+    auto name = filepath.filename().string();
 
     auto it = std::find_if(self->project_.shell_files.begin(), self->project_.shell_files.end(),
         [&](const ShellsFile& sf) { return &sf == self->selected_file_; });
@@ -426,7 +427,13 @@ void ShellsView::on_delete_file(GtkButton*, gpointer data) {
 
     self->selected_file_ = nullptr;
     self->populate_file_list();
-    self->project_.report_status("Removed shell file from project: " + name + " (file not deleted from disk)");
+
+    std::error_code ec;
+    if (std::filesystem::remove(filepath, ec))
+        self->project_.report_status("Deleted shell file: " + name);
+    else
+        self->project_.report_status("Error: could not delete " + name +
+            (ec ? ": " + ec.message() : ""));
 }
 
 void ShellsView::on_new_shell(GtkButton*, gpointer data) {

src/views/unit_editor.cpp

@@ -191,9 +191,9 @@ void UnitEditor::revert_current() {
     clear_dirty();
 }
 
-void UnitEditor::set_name_changed_callback(NameChangedCallback cb, void* data) {
-    name_cb_ = cb;
-    name_cb_data_ = data;
+void UnitEditor::set_unit_edited_callback(UnitEditedCallback cb, void* data) {
+    edit_cb_ = cb;
+    edit_cb_data_ = data;
 }
 
 void UnitEditor::on_edit_unit(GtkButton*, gpointer data) {
@@ -205,15 +205,17 @@ void UnitEditor::on_edit_unit(GtkButton*, gpointer data) {
         self->project_, self->grex_config_, self->project_.all_shells());
 
     if (result == UnitDialogResult::Save) {
-        // Sync state in case the unit name changed in the dialog
         auto new_name = self->current_unit_->name;
+        bool name_changed = (new_name != self->current_unit_name_);
         self->current_unit_name_ = new_name;
+        if (name_changed) {
             if (self->current_task_)
                 self->current_task_->name = new_name;
             gtk_label_set_text(GTK_LABEL(self->name_display_), new_name.c_str());
-        if (self->name_cb_)
-            self->name_cb_(new_name, self->name_cb_data_);
+        }
         self->mark_dirty();
+        if (self->edit_cb_)
+            self->edit_cb_(new_name, name_changed, self->edit_cb_data_);
     }
 }
 
@@ -234,7 +236,7 @@ void UnitEditor::on_select_unit(GtkButton*, gpointer data) {
         if (self->current_task_) self->current_task_->name = unit_name;
         Unit* unit = self->project_.find_unit(unit_name);
         self->load(self->current_task_, unit);
-        if (self->name_cb_) self->name_cb_(unit_name, self->name_cb_data_);
+        if (self->edit_cb_) self->edit_cb_(unit_name, true, self->edit_cb_data_);
     });
 }
 

src/views/unit_editor.h

@@ -41,8 +41,8 @@ public:
     void save_current();
     void revert_current();
 
-    using NameChangedCallback = void(*)(const std::string& new_name, void* data);
-    void set_name_changed_callback(NameChangedCallback cb, void* data);
+    using UnitEditedCallback = void(*)(const std::string& new_name, bool name_changed, void* data);
+    void set_unit_edited_callback(UnitEditedCallback cb, void* data);
 
 private:
     Project& project_;
@@ -62,8 +62,8 @@ private:
     GtkWidget* btn_save_unit_;
     GtkWidget* entry_comment_;
 
-    NameChangedCallback name_cb_ = nullptr;
-    void* name_cb_data_ = nullptr;
+    UnitEditedCallback edit_cb_ = nullptr;
+    void* edit_cb_data_ = nullptr;
 
     bool dirty_ = false;
 

src/views/units_view.cpp

@@ -145,8 +145,14 @@ UnitsView::UnitsView(Project& project, GrexConfig& grex_config)
     g_signal_connect(btn_move_up_, "clicked", G_CALLBACK(on_move_up), this);
     g_signal_connect(btn_move_down_, "clicked", G_CALLBACK(on_move_down), this);
     g_signal_connect(unit_listbox_, "row-activated", G_CALLBACK(on_unit_activated), this);
-    g_signal_connect(unit_listbox_, "row-selected", G_CALLBACK(+[](GtkListBox*, GtkListBoxRow*, gpointer d) {
-        static_cast<UnitsView*>(d)->update_move_buttons();
+    g_signal_connect(unit_listbox_, "row-selected", G_CALLBACK(+[](GtkListBox*, GtkListBoxRow* row, gpointer d) {
+        auto* self = static_cast<UnitsView*>(d);
+        self->update_move_buttons();
+        if (row && self->selected_file_) {
+            int idx = gtk_list_box_row_get_index(row);
+            if (idx >= 0 && idx < (int)self->selected_file_->units.size())
+                self->project_.check_unit_valid(self->selected_file_->units[idx]);
+        }
     }), this);
 
     g_signal_connect(btn_refresh, "clicked", G_CALLBACK(+[](GtkButton*, gpointer d) {
@@ -231,8 +237,15 @@ void UnitsView::populate_unit_list() {
 
     for (auto& u : selected_file_->units) {
         auto* row = gtk_list_box_row_new();
-        auto text = std::string("\u2022 ") + u.name;
-        auto* label = gtk_label_new(text.c_str());
+        auto* label = gtk_label_new(nullptr);
+        auto* escaped = g_markup_escape_text(u.name.c_str(), -1);
+        std::string markup;
+        if (project_.check_unit_valid(u))
+            markup = std::string("\u2022 ") + escaped;
+        else
+            markup = std::string("<span foreground=\"red\">\u2022 ") + escaped + "</span>";
+        g_free(escaped);
+        gtk_label_set_markup(GTK_LABEL(label), markup.c_str());
         gtk_label_set_xalign(GTK_LABEL(label), 0.0f);
         gtk_widget_set_margin_start(label, 8);
         gtk_widget_set_margin_end(label, 8);
@@ -403,7 +416,8 @@ void UnitsView::on_delete_file(GtkButton*, gpointer data) {
     auto* self = static_cast<UnitsView*>(data);
     if (!self->selected_file_) return;
 
-    auto name = self->selected_file_->filepath.filename().string();
+    auto filepath = self->selected_file_->filepath;
+    auto name = filepath.filename().string();
 
     auto it = std::find_if(self->project_.unit_files.begin(), self->project_.unit_files.end(),
         [&](const UnitFile& uf) { return &uf == self->selected_file_; });
@@ -412,7 +426,13 @@ void UnitsView::on_delete_file(GtkButton*, gpointer data) {
 
     self->selected_file_ = nullptr;
     self->populate_file_list();
-    self->project_.report_status("Removed unit file from project: " + name + " (file not deleted from disk)");
+
+    std::error_code ec;
+    if (std::filesystem::remove(filepath, ec))
+        self->project_.report_status("Deleted unit file: " + name);
+    else
+        self->project_.report_status("Error: could not delete " + name +
+            (ec ? ": " + ec.message() : ""));
 }
 
 void UnitsView::on_new_unit(GtkButton*, gpointer data) {