Improve UX, add popover tour, metadata, and hicolor icons

- Redesign tutorial tour from modal dialogs to popovers pointing at actual UI elements
- Add beginner-friendly improvements: help buttons, tooltips, welcome wizard enhancements
- Add AppStream metainfo with screenshots, branding, categories, keywords, provides
- Update desktop file with GTK category and SingleMainWindow
- Add hicolor icon theme with all sizes (16-512px)
- Fix debounce SourceId panic in rename step
- Various step UI improvements and bug fixes

pixstrip-core/src/preset.rs

@@ -10,6 +10,7 @@ pub struct Preset {
     pub name: String,
     pub description: String,
     pub icon: String,
+    pub icon_color: String,
     pub is_custom: bool,
     pub resize: Option<ResizeConfig>,
     pub rotation: Option<Rotation>,
@@ -27,6 +28,7 @@ impl Default for Preset {
             name: String::new(),
             description: String::new(),
             icon: "image-x-generic-symbolic".into(),
+            icon_color: String::new(),
             is_custom: true,
             resize: None,
             rotation: None,
@@ -90,6 +92,7 @@ impl Preset {
             name: "Blog Photos".into(),
             description: "Resize 1200px wide, JPEG quality High, strip all metadata".into(),
             icon: "image-x-generic-symbolic".into(),
+            icon_color: "accent".into(),
             is_custom: false,
             resize: Some(ResizeConfig::ByWidth(1200)),
             rotation: None,
@@ -107,6 +110,7 @@ impl Preset {
             name: "Social Media".into(),
             description: "Resize to fit 1080x1080, compress Medium, strip metadata".into(),
             icon: "system-users-symbolic".into(),
+            icon_color: "success".into(),
             is_custom: false,
             resize: Some(ResizeConfig::FitInBox {
                 max: Dimensions {
@@ -130,6 +134,7 @@ impl Preset {
             name: "Web Optimization".into(),
             description: "Convert to WebP, compress High, sequential rename".into(),
             icon: "web-browser-symbolic".into(),
+            icon_color: "accent".into(),
             is_custom: false,
             resize: None,
             rotation: None,
@@ -160,6 +165,7 @@ impl Preset {
             name: "Email Friendly".into(),
             description: "Resize 800px wide, JPEG quality Medium".into(),
             icon: "mail-unread-symbolic".into(),
+            icon_color: "warning".into(),
             is_custom: false,
             resize: Some(ResizeConfig::ByWidth(800)),
             rotation: None,
@@ -177,6 +183,7 @@ impl Preset {
             name: "Privacy Clean".into(),
             description: "Strip all metadata, no other changes".into(),
             icon: "security-high-symbolic".into(),
+            icon_color: "error".into(),
             is_custom: false,
             resize: None,
             rotation: None,
@@ -194,6 +201,7 @@ impl Preset {
             name: "Photographer Export".into(),
             description: "Resize 2048px, compress High, privacy metadata, rename by date".into(),
             icon: "camera-photo-symbolic".into(),
+            icon_color: "success".into(),
             is_custom: false,
             resize: Some(ResizeConfig::ByWidth(2048)),
             rotation: None,
@@ -224,6 +232,7 @@ impl Preset {
             name: "Archive Compress".into(),
             description: "Lossless compression, preserve metadata".into(),
             icon: "folder-symbolic".into(),
+            icon_color: "warning".into(),
             is_custom: false,
             resize: None,
             rotation: None,
@@ -241,6 +250,7 @@ impl Preset {
             name: "Print Ready".into(),
             description: "Maximum quality, convert to PNG, keep all metadata".into(),
             icon: "printer-symbolic".into(),
+            icon_color: "success".into(),
             is_custom: false,
             resize: None,
             rotation: None,
@@ -258,6 +268,7 @@ impl Preset {
             name: "Fediverse Ready".into(),
             description: "Resize 1920x1080, convert to WebP, compress High, strip metadata".into(),
             icon: "network-server-symbolic".into(),
+            icon_color: "accent".into(),
             is_custom: false,
             resize: Some(ResizeConfig::FitInBox {
                 max: Dimensions {

pixstrip-core/src/storage.rs

@@ -189,6 +189,7 @@ pub struct SessionState {
     pub resize_enabled: Option<bool>,
     pub resize_width: Option<u32>,
     pub resize_height: Option<u32>,
+    pub adjustments_enabled: Option<bool>,
     pub convert_enabled: Option<bool>,
     pub convert_format: Option<String>,
     pub compress_enabled: Option<bool>,