docs: refresh README for v0.2.4

- Install: add npm/npx (with the pnpm/bun opt-in), platform coverage,
  pin example v0.2.4; Cargo builds from source.
- Runtime helpers as a table, corrected: curl-impersonate is needed for
  IDX ownership discover/import and Yahoo fundamentals
  (IDX_PROVIDER=yahoo), not for stocks history; mutool only for legacy
  PDF reports. Everyday use needs neither.
- Quick start and Features now cover ownership (sync, ticker, entity,
  search, changes, concentration, cross-holders, graph; XLSX source on
  the IDX Data Kepemilikan Saham page) and the full stocks command set
  and providers. Every example was run against v0.2.4.
- Documentation index; script test suites.
- docs: example versions -> v0.2.4; npm publish needs 2FA and a fresh
  version number.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017a5Cv5Z1NzdYKgKnTiAF4E

docs/INSTALL.md

@@ -45,7 +45,7 @@ them yourself.
 Pass flags through the pipe with `sh -s --`:
 
 ```bash
-curl -fsSL https://raw.githubusercontent.com/0xrsydn/idx-cli/main/install.sh | sh -s -- --version v0.2.3 --dir ~/bin
+curl -fsSL https://raw.githubusercontent.com/0xrsydn/idx-cli/main/install.sh | sh -s -- --version v0.2.4 --dir ~/bin
 ```
 
 ## Supported platforms