docs(funding): enable GitHub Sponsors button + README support section

Two small changes, both customer-facing, both released into the
public-hold-period window for v1.0.0-rc1:

- .github/FUNDING.yml: uncomment `github: RelativisticJet` so the
  Sponsor button appears on the repo sidebar. GitHub Sponsors
  onboarding completed 2026-05-22; the previous all-commented state
  was the safe default while the platform account didn't exist yet
  (per the file's own header guidance — linking a platform you
  haven't onboarded creates a 404).
- README.md: insert "## 💖 Support This Project" section between
  Contributing and Trademark Notice. Links to
  https://github.com/sponsors/RelativisticJet plus star + issue-report
  CTAs. Phrases the value proposition as funded focus time on
  Whitelist Manager + adjacent open-source SOC tooling, matching the
  bio + introduction on the Sponsors profile page.

Repo metadata also updated separately via `gh repo edit --homepage
https://relativisticjet.github.io/wl_manager/` (Phase 2.11 finish —
the About-card "Website" field, which is set via the gear icon next
to "About" on the main repo page OR via the gh CLI, NOT via
Settings → General as previously stated; correcting that path
confusion here for future reference).

Closes the Sponsor-button + homepage-URL gaps surfaced in this
session's first-impression audit. Remaining first-impression items
(app icon, social preview image) tracked separately — both need
design input from the maintainer rather than mechanical edits.

Author: RelativisticJet

.github/FUNDING.yml

@@ -10,7 +10,7 @@
 # Order in this file does not affect rendering order; GitHub renders
 # them in its own canonical order regardless.
 
-# github: RelativisticJet      # GitHub Sponsors — requires onboarding
+github: RelativisticJet        # GitHub Sponsors — onboarding completed 2026-05-22
 # ko_fi: <username>            # https://ko-fi.com/<username>
 # buy_me_a_coffee: <username>  # https://www.buymeacoffee.com/<username>
 # liberapay: <username>        # https://liberapay.com/<username>

README.md

@@ -266,6 +266,23 @@ If you add a new validation wrapper (e.g. a path or URL sanitizer), update the
 corresponding `tests/semgrep/*-splunk.yaml` `pattern-sanitizers` list in the
 same PR, or legitimate callers of your wrapper will trip the rule.
 
+## 💖 Support This Project
+
+Whitelist Manager is built and maintained on personal time. If it saves your
+SOC effort — or you'd like to see it keep evolving — you can support the work:
+
+- **[Sponsor on GitHub](https://github.com/sponsors/RelativisticJet)** — one-time
+  or monthly contributions, any tier
+- **Star the repo** — helps other SOC teams discover the project
+- **Report issues** — bugs found during the v1.0.0-rc1 public hold period are
+  high-leverage; see [CONTRIBUTING.md](CONTRIBUTING.md) for the response-SLA
+  policy
+
+Sponsorships fund focused time on Whitelist Manager (post-rc1 priorities:
+dark-theme polish, multi-org adaptability, richer approval workflows) and on
+new open-source SOC tooling in the same audit-first, solo-maintainer-friendly
+style.
+
 ## Trademark Notice
 
 Splunk, Splunk Enterprise, and Splunk Enterprise Security are registered