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/cli/stocks.md

@@ -0,0 +1,67 @@
+---
+title: Stocks
+description: Quotes, history, company data, analysis and screening.
+---
+
+All `stocks` commands take IDX tickers (`BBCA`, or `BBCA.JK`). Every flag is
+listed in the [command reference](/cli/reference/).
+
+## Quotes and history
+
+```bash
+idx stocks quote BBCA BBRI,BMRI
+idx stocks history BBCA --period 1y --interval 1wk
+```
+
+`quote` takes several tickers, separated by spaces or commas, or `-` to read
+them from stdin. `history` takes `--period` (`1d` to `5y`) and `--interval`
+(`1d`, `1wk`, `1mo`).
+
+## Company data
+
+| Command | What it shows |
+| --- | --- |
+| `profile` | sector, industry, description, contacts and officers |
+| `financials` | income, balance sheet and cash flow statements (`--statement income,balance`) |
+| `earnings` | reported and estimated earnings |
+| `sentiment` | crowd sentiment |
+| `insights` | AI insights from the provider |
+| `news` | recent news |
+
+## Analysis
+
+| Command | What it computes |
+| --- | --- |
+| `technical` | trend, RSI, MACD, moving averages and signals |
+| `growth` | revenue and earnings growth rating |
+| `valuation` | P/E, P/B, ROE, net margin and EV/EBITDA, with a rating |
+| `risk` | debt to equity, current ratio and ROA, with a rating |
+| `fundamental` | growth, valuation and risk in one report |
+| `compare` | `fundamental` for several tickers side by side |
+
+```bash
+idx stocks fundamental BBRI
+idx stocks compare BBCA BBRI BMRI
+```
+
+## Screening
+
+```bash
+idx stocks screen --filter high-dividend --limit 20
+```
+
+Filters: `top-performers` (default), `worst-performers`, `high-dividend`,
+`low-pe`, `52w-high`, `52w-low`, `high-volume`, `large-cap`.
+
+Screen results pipe straight into `compare`:
+
+```bash
+idx stocks screen --filter high-dividend | jq -r '.[].symbol' | idx stocks compare -
+```
+
+## Providers
+
+MSN is the default for quotes, company data and screening; Yahoo serves
+price history. Switch with `IDX_PROVIDER=msn|yahoo` and
+`IDX_HISTORY_PROVIDER=auto|yahoo|msn`, or the matching
+[config keys](/start/config/).