feat(web): idx website and user docs (Astro Starlight)

Landing page plus docs for install, quickstart, config, the stocks and
ownership CLI, output and exit codes, the MCP server and per-agent setup,
agent usage, and an agent-led install page (agents/install.md) that a
coding agent follows from a one-line prompt.

- Every docs page is also served as Markdown at <path>.md; llms.txt and
  llms-full.txt come from starlight-llms-txt; a SKILL.md for skill-based
  harnesses is under /skills/idx/.
- The CLI reference and MCP tools pages are generated from idx --help and
  the tools golden; a new web-generated flake check fails when they drift.
- nix develop .#web provides bun; Cloudflare Pages builds web/ on pushes.
- Package homepage metadata points at https://idx.rasyidanaf.com.
- .cloudflare/ (the cf CLI's account cache) is git-ignored.

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

web/src/content/docs/about.md

@@ -0,0 +1,33 @@
+---
+title: About the data
+description: Where idx's data comes from, how fresh it is, and the project's terms.
+---
+
+## Sources
+
+| Data | Source | Freshness |
+| --- | --- | --- |
+| Quotes, company data, screening | MSN Money (default) or Yahoo Finance | live, cached for 5 minutes (quotes) or 1 hour (fundamentals) |
+| Price history | Yahoo Finance (default) or MSN | live |
+| Ownership | the KSEI register of holders above 1% ("Pemegang Saham di Atas 1%"), published monthly by IDX | the maintained snapshot is checked daily and rebuilt when IDX publishes a new month |
+
+Quotes from these providers can be delayed. The ownership register lists
+only holders above 1%; everything below is reported as free float.
+
+## The ownership snapshot
+
+`idx ownership sync` downloads a SQLite snapshot built from IDX's published
+reports and attached to the
+[GitHub release `ownership-snapshot-current`](https://github.com/0xrsydn/idx-cli/releases/tag/ownership-snapshot-current),
+with a manifest and SHA-256 checksum. You can build the same database
+yourself from IDX's files with `idx ownership import`.
+
+## Terms
+
+idx is open source under the MIT license:
+[github.com/0xrsydn/idx-cli](https://github.com/0xrsydn/idx-cli).
+
+It is not affiliated with, endorsed by, or connected to PT Bursa Efek
+Indonesia (IDX), PT Kustodian Sentral Efek Indonesia (KSEI), Microsoft or
+Yahoo. Data is provided as is, without warranty. Nothing here is investment
+advice.