chore: rewrite searchbar indexer for Vocs v2

[scode2277]

In this PR:

• Rewrote utils/searchbar-indexing.cjs from a re-indexer into a post-processor over Vocs v2's own search index.
• Re-added it to postdocs:build in package.json.

Why:
The old script worked around a Vocs v1 bug (its indexer skipped MDX with imports/components). Vocs v2 indexes correctly, but I decided to keep the script because it guarantees that dev files, as well as files not in the sidebar, are not searchable on the .org site.

What it does now:

• Instead of rebuilding the index, it takes the one Vocs v2 already correctly generates and filters it in place.
• Removes files we don't want indexed, like pages that are not in the sidebar or config pages.
• Removes the dev: true files, so the .org stays clean.
• Also removes the DevOnly-wrapped headings from the index of the Overview of Each Framework page.

[frameworks-volunteer]

Model: z-ai/glm-5.2 Reasoning: medium Provider: openrouter

Reviewed the rewrite of utils/searchbar-indexing.cjs from a full re-indexer into a post-processor over Vocs v2's own search index, plus the postdocs:build re-addition in package.json.

Security: No concerns. The new Function() eval on line 77 processes the sidebar array from vocs.config.ts — a first-party trusted config containing only plain data (strings, booleans, nested arrays). No template literals or expressions within the sidebar block. The eslint-disable comment documents the rationale. No external input reaches the eval. No secrets, no injection vectors, no suspicious deps.

QA: Changes match the PR description exactly. The bracket-matching parser for the sidebar is a clear improvement over the old line-by-line regex approach — it correctly inherits dev: true from parent groups. The DevOnly heading-stripping logic correctly matches the component usage in overview-of-each-framework.mdx. CI passes (lint, sidebar-reminder, Cloudflare Pages). postdocs:build ordering is correct — searchbar-indexing runs last, after vocs build generates the index.

One minor note (non-blocking): main() has no top-level try/catch (the old async version used .catch()). If readSidebarLinks() throws (e.g., sidebar structure changes), it produces a raw stack trace instead of a clean error message. Functionally equivalent — both exit(1) and fail the build — just slightly less graceful output. Not worth blocking on.

LGTM, approving.