chore: use support@wickra.org for contact/author email; drop dead sponsor link (#97)

Now that the wickra.org catch-all mailbox exists, move the project contact +
package-author email off the personal gmail to support@wickra.org across all
surfaces: CODE_OF_CONDUCT, SECURITY, CITATION.cff, Cargo.toml, the npm + PyPI
author fields, the release.yml npm author, and repo-metadata.toml. (The
package-author changes take effect on the next published release.)

repo-metadata.toml's [audit].forbidden still pins kingchencp@gmail.com (the
private commit email) as a banned substring — unchanged.

Also remove the FUNDING.yml custom "https://wickra.org/sponsor" entry: that
page 404s, so the Sponsor button linked to a dead URL. The GitHub Sponsors
entry (github: [kingchenc]) stays.

bindings/node/package.json

@@ -2,7 +2,7 @@
   "name": "wickra",
   "version": "0.3.1",
   "description": "Streaming-first technical indicators: incremental, fast, install-free. Node bindings powered by Rust.",
-  "author": "kingchenc <wickra.lib@gmail.com>",
+  "author": "kingchenc <support@wickra.org>",
   "main": "index.js",
   "types": "index.d.ts",
   "license": "PolyForm-Noncommercial-1.0.0",