fix(terminal): restrict GitHub shorthand owner to real slug rules

Owner segment now matches GitHub's user/org rules (ASCII alphanumerics
+ single hyphens, no dots/underscores, no leading/trailing/consecutive
hyphen, <=39 chars) instead of the lax repo charset. Prevents
slash-separated terminal tokens that fail path resolution (text/html,
foo.bar/baz, my_org/x) from producing bogus 'Open Link in Browser'
items. Repo names stay laxer (dots/underscores) to match real repos
like mrdoob/three.js.

Addresses Greptile P2 on manaflow-ai#5491.

Author: Supersynergy

Sources/GhosttyTerminalView.swift

@@ -11651,17 +11651,36 @@ class GhosttyNSView: NSView, NSUserInterfaceValidations {
         guard parts.count == 2 else { return nil }
         let owner = String(parts[0])
         let repo = String(parts[1])
-        let allowed = CharacterSet(
-            charactersIn: "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-._"
-        )
-        guard !owner.isEmpty, !repo.isEmpty,
-              owner.count <= 39, repo.count <= 100,
-              !owner.hasPrefix("-"), !owner.hasPrefix("."),
-              owner.unicodeScalars.allSatisfy(allowed.contains),
-              repo.unicodeScalars.allSatisfy(allowed.contains) else { return nil }
+        // The owner segment must match GitHub's real user/org slug rules:
+        // ASCII alphanumerics and single hyphens only — no dots or
+        // underscores, no leading/trailing/consecutive hyphen, ≤39 chars.
+        // This stops slash-separated terminal tokens that failed path
+        // resolution (e.g. `src/index.ts`, `dist/bundle.js`, MIME types
+        // like `text/html`) from producing bogus "Open Link" menu items.
+        // Repo names are laxer (dots/underscores allowed), matching GitHub.
+        guard Self.isPlausibleGitHubOwner(owner),
+              Self.isPlausibleGitHubRepo(repo) else { return nil }
         return URL(string: "https://github.com/\(owner)/\(repo)\(suffixPath)")
     }
 
+    private static let gitHubOwnerAllowed = CharacterSet(
+        charactersIn: "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-")
+    private static let gitHubRepoAllowed = CharacterSet(
+        charactersIn: "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-._")
+
+    private static func isPlausibleGitHubOwner(_ owner: String) -> Bool {
+        (1...39).contains(owner.count)
+            && !owner.hasPrefix("-") && !owner.hasSuffix("-")
+            && !owner.contains("--")
+            && owner.unicodeScalars.allSatisfy(gitHubOwnerAllowed.contains)
+    }
+
+    private static func isPlausibleGitHubRepo(_ repo: String) -> Bool {
+        (1...100).contains(repo.count)
+            && repo != "." && repo != ".."
+            && repo.unicodeScalars.allSatisfy(gitHubRepoAllowed.contains)
+    }
+
     private func writeStringToPasteboard(_ string: String) {
         let pasteboard = NSPasteboard.general
         pasteboard.clearContents()