add diff viewer prefs and task session shortcut

src/lib/diff-utils.ts

@@ -0,0 +1,50 @@
+const HUNK_PATTERN = /(^|\n)@@/m
+const FILE_MARKER_PATTERN = /(^|\n)(diff --git |--- |\+\+\+)/
+const BEGIN_PATCH_PATTERN = /^\*\*\* (Begin|End) Patch/
+const UPDATE_FILE_PATTERN = /^\*\*\* Update File: (.+)$/
+
+function stripCodeFence(value: string): string {
+  const trimmed = value.trim()
+  if (!trimmed.startsWith("```")) return trimmed
+  const lines = trimmed.split("\n")
+  if (lines.length < 2) return ""
+  const lastLine = lines[lines.length - 1]
+  if (!lastLine.startsWith("```")) return trimmed
+  return lines.slice(1, -1).join("\n")
+}
+
+export function normalizeDiffText(raw: string): string {
+  if (!raw) return ""
+  const withoutFence = stripCodeFence(raw.replace(/\r\n/g, "\n"))
+  const lines = withoutFence.split("\n").map((line) => line.replace(/\s+$/u, ""))
+
+  let pendingFilePath: string | null = null
+  const cleanedLines: string[] = []
+
+  for (const line of lines) {
+    if (!line) continue
+    if (BEGIN_PATCH_PATTERN.test(line)) {
+      continue
+    }
+    const updateMatch = line.match(UPDATE_FILE_PATTERN)
+    if (updateMatch) {
+      pendingFilePath = updateMatch[1]?.trim() || null
+      continue
+    }
+    cleanedLines.push(line)
+  }
+
+  if (pendingFilePath && !FILE_MARKER_PATTERN.test(cleanedLines.join("\n"))) {
+    cleanedLines.unshift(`+++ b/${pendingFilePath}`)
+    cleanedLines.unshift(`--- a/${pendingFilePath}`)
+  }
+
+  return cleanedLines.join("\n").trim()
+}
+
+export function isRenderableDiffText(raw?: string | null): raw is string {
+  if (!raw) return false
+  const normalized = normalizeDiffText(raw)
+  if (!normalized) return false
+  return HUNK_PATTERN.test(normalized)
+}

src/lib/markdown.ts

@@ -7,6 +7,43 @@ let currentTheme: "light" | "dark" = "light"
 let isInitialized = false
 let highlightSuppressed = false
 
+const extensionToLanguage: Record<string, string> = {
+  ts: "typescript",
+  tsx: "typescript",
+  js: "javascript",
+  jsx: "javascript",
+  py: "python",
+  sh: "bash",
+  bash: "bash",
+  json: "json",
+  html: "html",
+  css: "css",
+  md: "markdown",
+  yaml: "yaml",
+  yml: "yaml",
+  sql: "sql",
+  rs: "rust",
+  go: "go",
+  cpp: "cpp",
+  cc: "cpp",
+  cxx: "cpp",
+  hpp: "cpp",
+  h: "cpp",
+  c: "c",
+  java: "java",
+  cs: "csharp",
+  php: "php",
+  rb: "ruby",
+  swift: "swift",
+  kt: "kotlin",
+}
+
+export function getLanguageFromPath(path?: string | null): string | undefined {
+  if (!path) return undefined
+  const ext = path.split(".").pop()?.toLowerCase()
+  return ext ? extensionToLanguage[ext] : undefined
+}
+
 // Track loaded languages and queue for on-demand loading
 const loadedLanguages = new Set<string>()
 const queuedLanguages = new Set<string>()

src/lib/storage.ts

@@ -54,6 +54,7 @@ export class FileStorage {
           environmentVariables: {},
           modelRecents: [],
           agentModelSelections: {},
+          diffViewMode: "split",
         },
         recentFolders: [],
         opencodeBinaries: [],