fix(javascript): classify application input selection failures by cause

analyze_javascript_application reported every input-selection problem as
an artifact fault:

- a missing input path: "Artifact could not be read or written", with no
  path or reason;
- an unreadable selected directory: the same generic io failure;
- a regular file that is neither a directory nor an .asar, and a
  --artifact-format that contradicts the selection: "Artifact is invalid
  or has changed. Get a fresh copy and try again."

Report a missing path as an invalid input_path, an unreadable selection
as access_denied, a non-directory non-.asar file as unsupported_target
with the accepted inputs as remediation, and a contradicting format as an
invalid format with the observed kind as expected value. Failures inside
a selected artifact keep their existing classification.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/application/javascript/JavaScriptArtifactReconstruction.ts

@@ -1,6 +1,12 @@
-import { lstat, realpath } from "node:fs/promises";
+import { constants } from "node:fs";
+import { access, lstat, realpath } from "node:fs/promises";
 
 import { ArtifactReaderFailure } from "../../artifacts/ArtifactReader.js";
+import {
+  AnalysisAccessDeniedError,
+  AnalysisInputError,
+  AnalysisUnsupportedTargetError,
+} from "../../domain/analysisErrorCore.js";
 import { createJavaScriptArtifactReader as createReader } from "../../artifacts/javascript/JavaScriptArtifactReader.js";
 import type { JavaScriptApplicationGraph } from "../../domain/javascript/javascriptApplicationGraph.js";
 import type { JavaScriptSemanticGraph } from "../../domain/javascript/javascriptSemanticGraph.js";
@@ -58,7 +64,7 @@ export const reconstructJavaScriptArtifact = async (
   };
   const input = javascriptArtifactReconstructionInputSchema.parse(rawInput);
   abortIfNeeded(signal);
-  const path = await realpath(input.input_path);
+  const path = await resolveSelectedInput(input.input_path);
   const format = await resolveFormat(path, input);
   const snapshot = await scanCanonicalArtifactInventory(path, { signal });
   if (snapshot.manifest.root_format !== format)
@@ -159,6 +165,37 @@ export const reconstructJavaScriptArtifact = async (
   }
 };
 
+const OPERATION = "analyze_javascript_application";
+
+/**
+ * Resolve the caller-selected input. A missing or unreadable selection is a
+ * caller or host-permission failure, not a damaged artifact.
+ */
+const resolveSelectedInput = async (inputPath: string): Promise<string> => {
+  try {
+    const path = await realpath(inputPath);
+    await access(path, constants.R_OK);
+    return path;
+  } catch (cause: unknown) {
+    const code =
+      cause instanceof Error && "code" in cause ? String(cause.code) : "";
+    if (code === "EACCES" || code === "EPERM")
+      throw new AnalysisAccessDeniedError(OPERATION, inputPath, code, {
+        cause,
+      });
+    if (code === "ENOENT" || code === "ENOTDIR")
+      throw new AnalysisInputError(OPERATION, { cause }, [
+        {
+          path: ["input_path"],
+          reason: "invalid_value",
+          message: `No file or directory exists at the selected input path (${code}): ${inputPath}`,
+        },
+      ]);
+    throw cause;
+  }
+};
+
+/** The selected input's kind, checked against the caller's requested format. */
 const resolveFormat = async (
   path: string,
   input: JavaScriptArtifactReconstructionInput,
@@ -170,15 +207,24 @@ const resolveFormat = async (
       ? "asar"
       : undefined;
   if (observed === undefined)
-    throw new ArtifactReaderFailure(
-      "format",
-      `JavaScript artifact reconstruction accepts only a directory or .asar file: ${path}`,
+    throw new AnalysisUnsupportedTargetError(
+      OPERATION,
+      input.input_path,
+      "JavaScript application analysis accepts only a directory or an .asar file",
+      {
+        remediationAction:
+          "Select an extracted application directory, an app bundle, or an .asar file such as Contents/Resources/app.asar.",
+      },
     );
   if (input.format !== "auto" && input.format !== observed)
-    throw new ArtifactReaderFailure(
-      "format",
-      `Requested ${input.format} input but observed ${observed}: ${path}`,
-    );
+    throw new AnalysisInputError(OPERATION, undefined, [
+      {
+        path: ["format"],
+        reason: "invalid_value",
+        message: `Requested ${input.format} input, but the selected input is ${observed === "asar" ? "an .asar file" : "a directory"}: ${input.input_path}`,
+        expected: ["auto", observed],
+      },
+    ]);
   return observed;
 };