v0.5.0 — user-diversity coverage (Ruby/JVM, greenfield, fallback)

User-diversity coverage — handle the tails of the real-user distribution
(greenfield / unknown stack / non-Node-Python) that the detector previously left
silently under-served.

Added

• Ruby + JVM detection — detect.sh now implements the Gemfile (Ruby: rspec /
  minitest, rails / sinatra, bundler) and pom.xml / build.gradle[.kts] (Java /
  Kotlin: Maven / Gradle test+build commands, name from <artifactId>) markers that
  SKILL §2 already promised — closing a doc-over-promise where a Ruby/JVM repo was
  silently treated as stackless. render.sh renders their architects unchanged (it's
  stack-agnostic). Added to the monorepo member markers too.
• Edge-of-distribution guidance (SKILL §3): a blank/greenfield repo (no
  manifest) now gets only the universal §0 discipline spine + a "re-run once you add a
  stack" note (no fabricated stack); a manifest detect.sh doesn't cover
  (composer.json / mix.exs / *.csproj / deno.json …) gets a documented LLM fallback —
  read the manifest, hand-write a basic architect from the template — so an uncovered
  stack degrades gracefully instead of getting nothing.
• README documents stack coverage + that the generated harness is English (no
  localization of rules/structure).
• +9 tests (→ 159): Ruby, JVM, blank-slate detection + blank-slate render.