Add app update detection and multi-folder project support

Feature 1 - Update Detection: Query Gitea releases API on startup (3s
delay) and every 24h, compare patch versions by platform, show pulsing
"Update" button in TopBar with dialog for release notes/downloads.
Settings: auto-check toggle, manual check, dismiss per-version.

Feature 2 - Multi-Folder Projects: Replace single `path` with
`paths: Vec<ProjectPath>` (host_path + mount_name). Each folder mounts
to `/workspace/{mount_name}`. Auto-migrate old single-path JSON on load.
Container recreation via paths-fingerprint label. AddProjectDialog and
ProjectCard support add/remove/edit of multiple folders.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/src-tauri/src/commands/update_commands.rs

@@ -0,0 +1,117 @@
+use crate::models::{GiteaRelease, ReleaseAsset, UpdateInfo};
+
+const RELEASES_URL: &str =
+    "https://repo.anhonesthost.net/api/v1/repos/cybercovellc/triple-c/releases";
+
+#[tauri::command]
+pub fn get_app_version() -> String {
+    env!("CARGO_PKG_VERSION").to_string()
+}
+
+#[tauri::command]
+pub async fn check_for_updates() -> Result<Option<UpdateInfo>, String> {
+    let client = reqwest::Client::builder()
+        .timeout(std::time::Duration::from_secs(15))
+        .build()
+        .map_err(|e| format!("Failed to create HTTP client: {}", e))?;
+
+    let releases: Vec<GiteaRelease> = client
+        .get(RELEASES_URL)
+        .header("Accept", "application/json")
+        .send()
+        .await
+        .map_err(|e| format!("Failed to fetch releases: {}", e))?
+        .json()
+        .await
+        .map_err(|e| format!("Failed to parse releases: {}", e))?;
+
+    let current_version = env!("CARGO_PKG_VERSION");
+    let is_windows = cfg!(target_os = "windows");
+
+    // Filter releases by platform tag suffix
+    let platform_releases: Vec<&GiteaRelease> = releases
+        .iter()
+        .filter(|r| {
+            if is_windows {
+                r.tag_name.ends_with("-win")
+            } else {
+                !r.tag_name.ends_with("-win")
+            }
+        })
+        .collect();
+
+    // Find the latest release with a higher patch version
+    // Version format: 0.1.X or v0.1.X (tag may have prefix/suffix)
+    let current_patch = parse_patch_version(current_version).unwrap_or(0);
+
+    let mut best: Option<(&GiteaRelease, u32)> = None;
+    for release in &platform_releases {
+        if let Some(patch) = parse_patch_from_tag(&release.tag_name) {
+            if patch > current_patch {
+                if best.is_none() || patch > best.unwrap().1 {
+                    best = Some((release, patch));
+                }
+            }
+        }
+    }
+
+    match best {
+        Some((release, _)) => {
+            let assets = release
+                .assets
+                .iter()
+                .map(|a| ReleaseAsset {
+                    name: a.name.clone(),
+                    browser_download_url: a.browser_download_url.clone(),
+                    size: a.size,
+                })
+                .collect();
+
+            // Reconstruct version string from tag
+            let version = extract_version_from_tag(&release.tag_name)
+                .unwrap_or_else(|| release.tag_name.clone());
+
+            Ok(Some(UpdateInfo {
+                version,
+                tag_name: release.tag_name.clone(),
+                release_url: release.html_url.clone(),
+                body: release.body.clone(),
+                assets,
+                published_at: release.published_at.clone(),
+            }))
+        }
+        None => Ok(None),
+    }
+}
+
+/// Parse patch version from a semver string like "0.1.5" -> 5
+fn parse_patch_version(version: &str) -> Option<u32> {
+    let clean = version.trim_start_matches('v');
+    let parts: Vec<&str> = clean.split('.').collect();
+    if parts.len() >= 3 {
+        parts[2].parse().ok()
+    } else {
+        None
+    }
+}
+
+/// Parse patch version from a tag like "v0.1.5", "v0.1.5-win", "0.1.5" -> 5
+fn parse_patch_from_tag(tag: &str) -> Option<u32> {
+    let clean = tag.trim_start_matches('v');
+    // Remove platform suffix
+    let clean = clean.strip_suffix("-win").unwrap_or(clean);
+    parse_patch_version(clean)
+}
+
+/// Extract a clean version string from a tag like "v0.1.5-win" -> "0.1.5"
+fn extract_version_from_tag(tag: &str) -> Option<String> {
+    let clean = tag.trim_start_matches('v');
+    let clean = clean.strip_suffix("-win").unwrap_or(clean);
+    // Validate it looks like a version
+    let parts: Vec<&str> = clean.split('.').collect();
+    if parts.len() >= 3 && parts.iter().all(|p| p.parse::<u32>().is_ok()) {
+        Some(clean.to_string())
+    } else {
+        None
+    }
+}