feat(artifact): add extractArtifacts message scanner

Scans Message[] for artifact tool_use/tool_result pairs, parses URL/id/expires
from the upload response string, and returns ArtifactInfo[] newest-first.

Co-Authored-By: glm-5.2 <zai-org@claude-code-best.win>

src/commands/artifacts/scanner.ts

@@ -0,0 +1,97 @@
+import { basename } from 'path'
+import type { Message } from 'src/types/message.js'
+
+export type ArtifactInfo = {
+  toolUseId: string
+  filePath: string
+  basename: string
+  hash?: string
+  url?: string
+  expiresAt?: string
+  rawContent: string
+  isError: boolean
+}
+
+const URL_REGEX = /https?:\/\/\S+\.html\b/
+const ID_REGEX = /\bid:\s*([A-Za-z0-9_-]+)/
+const EXPIRES_REGEX = /\bexpires:\s*([0-9T:.Z+-]+)/
+
+export function extractArtifacts(messages: Message[]): ArtifactInfo[] {
+  const results: ArtifactInfo[] = []
+
+  for (const message of messages) {
+    if (message.type !== 'assistant') continue
+    const content = message.message?.content
+    if (!Array.isArray(content)) continue
+
+    for (const block of content) {
+      if (typeof block !== 'object' || block === null) continue
+      if (!('type' in block)) continue
+      const b = block as Record<string, unknown>
+      if (b.type !== 'tool_use') continue
+      if (b.name !== 'artifact') continue
+
+      const toolUseId = b.id as string
+      const input = b.input as { file_path?: string } | undefined
+      const filePath = input?.file_path ?? '<unknown>'
+
+      const resultBlock = findToolResult(messages, toolUseId)
+      if (!resultBlock) continue
+
+      const rawContent =
+        typeof resultBlock.content === 'string'
+          ? resultBlock.content
+          : Array.isArray(resultBlock.content)
+            ? resultBlock.content
+                .map(c =>
+                  typeof c === 'string'
+                    ? c
+                    : 'text' in c
+                      ? (c as { text: string }).text
+                      : '',
+                )
+                .join('')
+            : ''
+
+      const isError = resultBlock.is_error === true
+      const urlMatch = rawContent.match(URL_REGEX)
+      const idMatch = rawContent.match(ID_REGEX)
+      const expiresMatch = rawContent.match(EXPIRES_REGEX)
+
+      results.push({
+        toolUseId,
+        filePath,
+        basename: basename(filePath),
+        hash: idMatch?.[1],
+        url: urlMatch?.[0],
+        expiresAt: expiresMatch?.[1],
+        rawContent,
+        isError,
+      })
+    }
+  }
+
+  // newest first
+  return results.reverse()
+}
+
+function findToolResult(
+  messages: Message[],
+  toolUseId: string,
+): { content: unknown; is_error?: boolean } | null {
+  for (const message of messages) {
+    if (message.type !== 'user') continue
+    const content = message.message?.content
+    if (!Array.isArray(content)) continue
+
+    for (const block of content) {
+      if (typeof block !== 'object' || block === null) continue
+      if (!('type' in block)) continue
+      const b = block as Record<string, unknown>
+      if (b.type !== 'tool_result') continue
+      if (b.tool_use_id !== toolUseId) continue
+      return { content: b.content, is_error: b.is_error as boolean | undefined }
+    }
+  }
+  return null
+}