The docs pages have the Markdown twins they name (#209)

ddiff --git a/server/agent-pages.js b/server/agent-pages.js
iindex caed6ec..7707d42 100644
---- a/server/agent-pages.js
++++ b/server/agent-pages.js
@@@ -3,12 +3,39 @@
  // view builders the routes use (http/pages.js and http/docs.js + render/layout.js's renderPage), so a twin
  // cannot drift from its page. Anonymous only: /projects, /staff and the API are never rendered here.
  const { createPageViews } = require('./http/pages');
--const { createDocsViews } = require('./http/docs');
++const { createDocsViews, createDocsRoutes } = require('./http/docs');
++
++// The docs pages the docs router builds inline (contracts, capabilities, events, services, tools, SDK, …) are twinned by
++// running that router signed out: each named a twin that answered 404 (11-03, tools/twin-named-check.js).
++const DOCS_ROUTER_RE = /^\/docs\/(?:contracts|capabilities|events|services|tools|billing|limits|export|sdk|adr|updates)(?:\/[^/]+)?$/;
++
++/** One GET through `router`, as a signed-out visitor; the HTML of a 200 answer, or null. */
++function renderThrough(router, mount, path, query) {
++    return new Promise((resolve) => {
++        const search = query ? query.toString() : '';
++        const sub = path.slice(mount.length) || '/';
++        const req = {
++            method: 'GET', url: sub + (search ? `?${search}` : ''), originalUrl: path + (search ? `?${search}` : ''), baseUrl: mount, path: sub,
++            params: {}, query: Object.fromEntries(new URLSearchParams(search)), headers: { accept: 'text/html', host: 'localhost' },
++            viewer: { kind: 'anonymous' }, get(name) { return this.headers[String(name).toLowerCase()]; },
++        };
++        const headers = {};
++        const res = {
++            statusCode: 200,
++            get: (k) => headers[String(k).toLowerCase()], set(k, v) { headers[String(k).toLowerCase()] = v; return this; },
++            status(code) { this.statusCode = code; return this; }, type(t) { headers['content-type'] = t; return this; },
++            send(body) { resolve(this.statusCode === 200 && /html/.test(String(headers['content-type'] || '')) && typeof body === 'string' ? body : null); return this; },
++            json() { resolve(null); return this; }, end() { resolve(null); return this; }, redirect() { resolve(null); return this; },
++        };
++        try { router.handle(req, res, () => resolve(null)); } catch { resolve(null); }
++    });
++}
  const { renderPage } = require('./render/layout');
  
  function createAgentPages(ctx) {
      const pages = createPageViews(ctx);
      const docs = createDocsViews(ctx);
++    const docsRouter = createDocsRoutes(ctx);
  
      const twin = (o, path, query) => {
          if (!o) return null;
@@@ -32,6 +59,10 @@ function createAgentPages(ctx) {
          if (path === '/policy/transparency') return twin(pages.policyTransparency(), path);
          if (path === '/docs') return twin(docs.index(), path);
          if (path === '/docs/api') return twin(docs.apiExplorer(), path);
++        if (DOCS_ROUTER_RE.test(path)) {
++            const htmlOut = await renderThrough(docsRouter, '/docs', path, query);
++            return htmlOut ? { html: htmlOut } : null;
++        }
          const api = /^\/docs\/api\/([^/]+)$/.exec(path);
          if (api) {
              const id = decodeURIComponent(api[1]);
ddiff --git a/server/http/discovery.js b/server/http/discovery.js
iindex dd5c883..4647ef3 100644
---- a/server/http/discovery.js
++++ b/server/http/discovery.js
@@@ -224,12 +224,12 @@ function createDiscoveryRoutes(ctx) {
                  ] },
                  { title: 'Reference', links: [
                      { title: 'API explorer', url: abs('/docs/api'), note: 'each service\'s OpenAPI document, per page as .json' },
--                    { title: 'Contracts', url: abs('/docs/contracts'), html: true, note: 'schemas, field tables and fixtures, per page as .json' },
--                    { title: 'Capabilities', url: abs('/docs/capabilities'), html: true },
--                    { title: 'Events', url: abs('/docs/events'), html: true },
--                    { title: 'Services', url: abs('/docs/services'), html: true },
--                    { title: 'Tools', url: abs('/docs/tools'), html: true },
--                    { title: 'SDK', url: abs('/docs/sdk'), html: true },
++                    { title: 'Contracts', url: abs('/docs/contracts'), note: 'schemas, field tables and fixtures, per page as .json' },
++                    { title: 'Capabilities', url: abs('/docs/capabilities') },
++                    { title: 'Events', url: abs('/docs/events') },
++                    { title: 'Services', url: abs('/docs/services') },
++                    { title: 'Tools', url: abs('/docs/tools') },
++                    { title: 'SDK', url: abs('/docs/sdk') },
                  ] },
                  { title: 'Extend OpenVibe', links: [
                      { title: 'Mod the network', url: abs('/mod'), note: 'every way to extend OpenVibe today, and where packaged mods stand' },
ddiff --git a/test/discovery.test.js b/test/discovery.test.js
iindex da59b65..a499769 100644
---- a/test/discovery.test.js
++++ b/test/discovery.test.js
@@@ -61,7 +61,7 @@ const PRIVATE = ['/projects', '/staff', '/auth/', '/oauth/test-callback'];
              assert.ok(/\n## Optional\n/.test(r.text), 'no Optional section');
              assert.strictEqual(r.text.lastIndexOf('\n## '), r.text.indexOf('\n## Optional'), 'Optional is the last section');
              // A page whose twin answers 404 keeps its URL and says (HTML); a file keeps its URL.
--            assert.ok(r.text.includes('(https://openvibe.services/docs/contracts) (HTML)'), 'the twin-less contracts page is marked (HTML)');
++            assert.ok(r.text.includes('(https://openvibe.services/docs/contracts.md)') && r.text.includes('(https://openvibe.services/oauth) (HTML)'), 'the docs pages link their twins; a page with none is marked (HTML)');
              assert.ok(!/\]\(https:\/\/openvibe\.services\/mcp\)/.test(r.text), '/mcp must not be a page link');
              assert.ok(/MCP server: POST https:\/\/openvibe\.services\/mcp/.test(r.text), 'the MCP endpoint is named in the details');
              const own = [...r.text.matchAll(/\]\((https:\/\/openvibe\.services[^)\s]*)\)( \(HTML\))?/g)];
ddiff --git a/test/docs.test.js b/test/docs.test.js
iindex 258d3c7..41131c5 100644
---- a/test/docs.test.js
++++ b/test/docs.test.js
@@@ -28,6 +28,18 @@ const sdkPkg = require('openvibe-sdk/package.json');
          assert.ok(contracts.resolve('services.app-manifest@1'));
      });
  
++    await check('the docs pages have the Markdown twins they name (11-03: /docs/contracts and the rest answered 404)', async () => {
++        for (const p of ['/docs/contracts', '/docs/capabilities', '/docs/events', '/docs/sdk', '/docs/contracts/errors.problem', '/docs/sdk/core']) {
++            const page = await t.get(p);
++            assert.match(page.headers.get('link') || page.text, /text\/markdown/, `${p} names a twin`);
++            const twin = await t.get(`${p}.md`);
++            assert.strictEqual(twin.status, 200, `${p}.md`);
++            assert.match(twin.headers.get('content-type') || '', /^text\/markdown/, `${p}.md is Markdown`);
++            assert.ok(!/<\/?(div|table|td|tr|section)\b/i.test(twin.text), `${p}.md is Markdown, not HTML`);
++        }
++        assert.strictEqual((await t.get('/docs/contracts/no-such-contract.md')).status, 404, 'no page, no twin');
++    });
++
      await check('every docs page states the versions it was generated from', async () => {
          for (const p of ['/docs', '/docs/contracts', '/docs/capabilities', '/docs/events', '/docs/sdk', '/docs/contracts/errors.problem', '/docs/sdk/core']) {
              const r = await t.get(p);