feat(browser): trace captured website source-map locations (#897)

* refactor(browser): share captured-script acquisition boundaries

Reuse stable capture/source acquisition and identity validation for module
and source-map analysis. Preserve host I/O, malformed input, unavailable
source and digest mismatch diagnostics.

Refs #851

Assisted-by: Yukari (gensokyo-skills:yukari-boundary-analysis)
Assisted-by: Kogasa (gensokyo-skills:kogasa-surprise-testing)

* feat(browser): trace captured website source-map locations

Refs #851. Preserve selected capture/map byte identity, duplicate mappings and embedded source evidence through the pinned upstream codec.

Assisted-by: Yukari (gensokyo-skills:yukari-boundary-analysis)
Assisted-by: Kogasa (gensokyo-skills:kogasa-surprise-testing)

* test(browser): verify source-map artifacts and synchronize generated contracts

Cover byte-preserving map reads and actionable filesystem constraints. Refresh generated public schemas and metadata on current main.

Assisted-by: Yukari (gensokyo-skills:yukari-boundary-analysis)
Assisted-by: Kogasa (gensokyo-skills:kogasa-surprise-testing)

* fix(browser): preserve inert source-map URL context

The selected URL is local codec context and grants no transport authority. Preserve its reported text and verify normal/userinfo contexts through real public interfaces, alongside independent manifest byte identity.

Assisted-by: Yukari (gensokyo-skills:yukari-boundary-analysis)
Assisted-by: Kogasa (gensokyo-skills:kogasa-surprise-testing)

src/javascript/sourceMaps/SourceMapCodecProcess.ts

@@ -0,0 +1,59 @@
+import { readStableArtifact } from "../../artifacts/readStableArtifact.js";
+import { WEB_SOURCE_MAP_LIMITS } from "../../domain/webSourceLocation.js";
+import { traceSourceMap } from "./TraceSourceMap.js";
+import { SourceMapFormatFailure } from "./SourceMapFormat.js";
+import {
+  sourceMapCodecInputSchema,
+  sourceMapCodecReplySchema,
+} from "./SourceMapCodecProtocol.js";
+import { z } from "zod";
+
+/** Dedicated process entrypoint invoked only for an explicitly selected map. */
+const execute = async (): Promise<string> => {
+  try {
+    const path = process.argv[2];
+    if (path === undefined)
+      throw new SourceMapFormatFailure(
+        "format",
+        "Codec request path is missing.",
+      );
+    const data = await readStableArtifact(
+      path,
+      WEB_SOURCE_MAP_LIMITS.outputBytes,
+    );
+    const text = new TextDecoder("utf-8", { fatal: true }).decode(data.bytes);
+    const value: unknown = JSON.parse(text);
+    const input = sourceMapCodecInputSchema.parse(value);
+    if (Buffer.byteLength(input.text) > WEB_SOURCE_MAP_LIMITS.mapBytes)
+      throw new SourceMapFormatFailure(
+        "limit",
+        "Source map exceeds the 4 MiB codec input budget.",
+      );
+    const report = traceSourceMap(input.text, input.url, input.position);
+    const reply = JSON.stringify(
+      sourceMapCodecReplySchema.parse({ state: "success", report }),
+    );
+    if (Buffer.byteLength(reply) > WEB_SOURCE_MAP_LIMITS.outputBytes)
+      throw new SourceMapFormatFailure(
+        "limit",
+        "Complete source-map point evidence exceeds the 32 MiB output budget; no partial evidence was returned.",
+      );
+    return reply;
+  } catch (cause: unknown) {
+    if (
+      !(
+        cause instanceof SourceMapFormatFailure ||
+        cause instanceof z.ZodError ||
+        cause instanceof SyntaxError
+      )
+    )
+      throw cause;
+    return JSON.stringify({
+      state: "failure",
+      reason: cause instanceof SourceMapFormatFailure ? cause.reason : "format",
+      message: cause.message,
+    });
+  }
+};
+
+process.stdout.write(await execute());