docs(readme): add restrained star + issue CTA below tagline

A single italic line under the existing personal-note italic, asking
readers to ⭐ the repo if they get value, and to file issues — framed
explicitly as "issues are even more useful than stars" so the CTA reads
as feedback-seeking rather than vanity-metric chasing.

Tone matches the rest of README: low-key, single-maintainer self-deprecating,
no marketing voice. No "save money / free / $0" verbiage. Coexists with the
existing buy-me-a-coffee personal-note line above it (different ask:
funding vs. social-proof).

This is doc-only. ALIGNMENT.md Rule 5 (cli.js citation) does not apply.
Same pattern as #68 / #69 / #71 / #78.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

README.md

@@ -6,6 +6,8 @@
 
 *Open source from day one, used daily by my family, maintained on nights and weekends. If OCP saves you money too, you can [☕ buy me a coffee](https://buymeacoffee.com/dtzp555) — [full story below](#support-ocp).*
 
+*If OCP saves you a setup, a ⭐ helps other folks discover it. Issue reports are even more useful — that's the highest-quality feedback this project gets.*
+
 OCP turns your Claude Pro/Max subscription into a standard OpenAI-compatible API on localhost. Any tool that speaks the OpenAI protocol can use it — no separate API key, no extra billing.
 
 ```