Release 0.14.0: public /docs user guide (DOCS.md served at /docs)

Ships DOCS.md and the /docs route — a plain-prose translation of
SPEC.md for users, distinct from the binding spec. Originating need
was the admin-vs-owner role distinction on /admin/users (§6.1);
response is a single guide that covers the framework's user-facing
surfaces end-to-end (roles, proposing, branches, PRs, graduation,
notifications). Mirrors /philosophy: markdown file at repo root +
sibling backend loader + MarkdownPreview render. No schema migration.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

frontend/src/components/Docs.jsx

@@ -0,0 +1,51 @@
+// `/docs` — the user-facing guide.
+//
+// Sibling of Philosophy.jsx: same chrome, same data path, different
+// source file. Renders DOCS.md verbatim with light chrome around it.
+// Reachable anonymously, same as `/philosophy`, so a visitor can read
+// the guide before deciding to sign in.
+
+import { useEffect, useState } from 'react'
+import { Link, useNavigate } from 'react-router-dom'
+import MarkdownPreview from './MarkdownPreview.jsx'
+import { getDocs } from '../api.js'
+
+export default function Docs({ authenticated }) {
+  const [body, setBody] = useState('')
+  const [error, setError] = useState(null)
+  const [loading, setLoading] = useState(true)
+  const navigate = useNavigate()
+
+  useEffect(() => {
+    let active = true
+    getDocs()
+      .then(r => { if (active) setBody(r.body || '') })
+      .catch(e => { if (active) setError(e.message || String(e)) })
+      .finally(() => { if (active) setLoading(false) })
+    return () => { active = false }
+  }, [])
+
+  return (
+    <div className="philosophy-page">
+      <header className="philosophy-header">
+        <button
+          className="philosophy-back"
+          onClick={() => (history.length > 1 ? navigate(-1) : navigate('/'))}
+        >
+          ← Back
+        </button>
+        <span className="philosophy-title">User guide</span>
+        {!authenticated && (
+          <Link className="philosophy-signin" to="/">Home</Link>
+        )}
+      </header>
+      <article className="philosophy-body">
+        {loading && <p className="muted">Loading…</p>}
+        {error && <p className="error">Could not load the guide: {error}</p>}
+        {!loading && !error && (
+          <MarkdownPreview content={body} />
+        )}
+      </article>
+    </div>
+  )
+}