Quest experience awards and the Network levels page (#262)

ddiff --git a/migrations/0012_experience_rewards.sql b/migrations/0012_experience_rewards.sql
nnew file mode 100644
iindex 0000000..d15c8b7
---- /dev/null
++++ b/migrations/0012_experience_rewards.sql
@@@ -0,0 +1,5 @@
++-- phase: expand
++-- Completion is the durable outbox: retries reuse its existing id.
++ALTER TABLE quest_completions ADD COLUMN IF NOT EXISTS experience_state text NOT NULL DEFAULT 'pending'
++    CHECK (experience_state IN ('pending', 'awarded', 'skipped'));
++CREATE INDEX IF NOT EXISTS quest_completions_experience_pending ON quest_completions(completed_at) WHERE experience_state = 'pending';
ddiff --git a/package-lock.json b/package-lock.json
iindex 66e28df..d3fc5fa 100644
---- a/package-lock.json
++++ b/package-lock.json
@@@ -17,7 +17,7 @@
          "iovalkey": "^0.4.0",
          "openvibe-contracts": "https://codeload.github.com/OpenVibers/OpenVibe.Contracts/tar.gz/refs/tags/v0.384.0",
          "openvibe-publishing": "https://codeload.github.com/OpenVibers/OpenVibe.Publishing/tar.gz/refs/tags/v1.7.0",
--        "openvibe-sdk": "https://codeload.github.com/OpenVibers/OpenVibe.SDK/tar.gz/refs/tags/v0.125.0",
++        "openvibe-sdk": "https://codeload.github.com/OpenVibers/OpenVibe.SDK/tar.gz/refs/tags/v0.136.0",
          "openvibe-shared": "https://codeload.github.com/OpenVibers/OpenVibe.Shared/tar.gz/refs/tags/v4.186.0",
          "pg": "^8.23.0"
        },
@@@ -1181,9 +1181,9 @@
        }
      },
      "node_modules/openvibe-sdk": {
--      "version": "0.125.0",
--      "resolved": "https://codeload.github.com/OpenVibers/OpenVibe.SDK/tar.gz/refs/tags/v0.125.0",
--      "integrity": "sha512-hGYmiaYLk/QrZC7w0opFAlEQi9fgDct0qcwc4cVBNBzCPm8HSRZlibYBe5x+NVshM3kqgQ6LZihqvFj1LP51bg==",
++      "version": "0.136.0",
++      "resolved": "https://codeload.github.com/OpenVibers/OpenVibe.SDK/tar.gz/refs/tags/v0.136.0",
++      "integrity": "sha512-iPi6gijL8mE961KMgIxh4wFey2GlJMOhmnQQnqPFr1qEY6YGE/3hzLY7w1JQUUSFZrR6/f822CQzPpPIFiMB7g==",
        "license": "MIT",
        "bin": {
          "openvibe-download": "bin/openvibe-download.js"
ddiff --git a/package.json b/package.json
iindex a412150..1c4042d 100644
---- a/package.json
++++ b/package.json
@@@ -24,7 +24,7 @@
      "iovalkey": "^0.4.0",
      "openvibe-contracts": "https://codeload.github.com/OpenVibers/OpenVibe.Contracts/tar.gz/refs/tags/v0.384.0",
      "openvibe-publishing": "https://codeload.github.com/OpenVibers/OpenVibe.Publishing/tar.gz/refs/tags/v1.7.0",
--    "openvibe-sdk": "https://codeload.github.com/OpenVibers/OpenVibe.SDK/tar.gz/refs/tags/v0.125.0",
++    "openvibe-sdk": "https://codeload.github.com/OpenVibers/OpenVibe.SDK/tar.gz/refs/tags/v0.136.0",
      "openvibe-shared": "https://codeload.github.com/OpenVibers/OpenVibe.Shared/tar.gz/refs/tags/v4.186.0",
      "pg": "^8.23.0"
    },
ddiff --git a/server/app.js b/server/app.js
iindex cc4c4e1..14e7499 100644
---- a/server/app.js
++++ b/server/app.js
@@@ -60,6 +60,7 @@ async function createApp(opts = {}) {
      const sso = createSso({ config, keys, fetchImpl, now: s.now, log });
      const principal = createPrincipal({ config, keys });
      const coins = createCoins({ config, s, fetchImpl, log });
++    const levels = require('./quests/levels').createLevels({ config, s, fetchImpl });
      const items = createItems({ config, s, fetchImpl, log });
      // Account export and deletion (ADR-033, ./identity/account-data.js): the three tables that hold a person's rows.
      // The sender posts to Network's internal export/deletion routes with this service's own client-credentials token;
@@@ -77,7 +78,7 @@ async function createApp(opts = {}) {
      const eventsConsumer = createEventsConsumer({ db: s.db, s, secrets: config.events.secrets, coins, items, accountData, accountSend, appQuests, daily, now: s.now, log });
      // The quests in OpenVibe.Search (./search-index.js), swept on its own timer once server/index.js starts it.
      const searchIndex = opts.searchIndex || createSearchIndex({ config, s, log });
--    const ctx = { config, s, keys, sso, principal, coins, items, daily, glyphs, eventsConsumer, accountData, accountSend, searchIndex, appQuests, log };
++    const ctx = { config, s, keys, sso, principal, levels, coins, items, daily, glyphs, eventsConsumer, accountData, accountSend, searchIndex, appQuests, log };
  
      const app = express();
      // GET /openapi.json (SEO-3): this service's public API as OpenAPI 3.1, generated from the contracts
ddiff --git a/server/http/pages.js b/server/http/pages.js
iindex 8ebdbf9..bdf3fa8 100644
---- a/server/http/pages.js
++++ b/server/http/pages.js
@@@ -51,6 +51,19 @@ function questDescription(quest) {
  function createPageRoutes(ctx) {
      const { config, s, coins } = ctx;
      const r = asyncRouter();
++    r.get('/levels', async (req, res) => {
++        res.set('Cache-Control', req.viewer?.kind === 'user' ? 'private, no-store' : 'public, max-age=30');
++        const client = ctx.levels.readClient(req.viewer?.token);
++        let board, mine;
++        try {
++            [board, mine] = await Promise.all([client.board(), req.viewer?.username ? client.get(req.viewer.username) : null]);
++        } catch { return page(req, res, { title: 'Levels', body: html`<h1>Levels</h1><p>Experience is temporarily unavailable. Try again shortly.</p>` }, 503); }
++        const renderBoard = (label, data) => html`<section><h2>${label}</h2><ol>${data.top.map(e => html`<li value="${e.rank}"><a href="https://openvibe.network/@${encodeURIComponent(e.username)}">${e.username}</a> — Level ${e.level} · ${e.xp} experience</li>`)}</ol>${data.me ? html`<p>Your place: ${data.me.rank}</p><ol>${data.around.map(e => html`<li value="${e.rank}">${e.username} — Level ${e.level} · ${e.xp} experience</li>`)}</ol>` : ''}</section>`;
++        return page(req, res, { title: 'Levels', styles: KIT_STYLES, body: html`<h1>Levels</h1>
++            ${mine ? html`<section><h2>Your level: ${mine.level}</h2><p>${mine.xp} experience · ${mine.next_at - mine.xp} to the next level</p><progress aria-label="Experience to next level" value="${mine.into}" max="${mine.span}"></progress><h3>Recent experience</h3><ul>${mine.recent.map(e => html`<li>${e.name} · ${e.amount} · <time datetime="${e.at}">${e.at.slice(0, 10)}</time></li>`)}</ul></section>` : html`<p><a href="/me">Sign in to see your level</a></p>`}
++            ${renderBoard('All time', board.all_time)}${renderBoard('This week', board.week)}
++            <section><h2>How experience is earned</h2><p>Earned OpenCoins add the same amount of experience. Finishing a platform quest adds 25 extra experience. Experience is never bought or spent.</p><p><a href="https://openvibe.network/my#profile">Choose whether to appear on the leaderboard</a>. Your profile still shows your level.</p></section>` });
++    });
      const PUBLIC_CACHE = cache.htmlHeaders({ maxAge: 300 });
      // The pages with a Markdown twin (openvibe-shared/agent-layer): the public ones only.
      const TWIN_PATH_RE = /^\/(?:how-it-works|build-a-step-type|updates|quests|quests\/[^/]+|series\/[^/]+|apps\/quests\/[^/]+)?$/;
ddiff --git a/server/index.js b/server/index.js
iindex 364edea..9eecc62 100644
---- a/server/index.js
++++ b/server/index.js
@@@ -47,6 +47,10 @@ async function start() {
      const secret = config.events.secrets[0] || '';
      const subscriptions = require('./events-consumer').startSubscriptions({ config, port: config.port, secret });
      const timers = [];
++    const levelsTimer = setInterval(() => ctx.levels.retryPending().catch(() => {}), 30000);
++    levelsTimer.unref();
++    timers.push(levelsTimer);
++    ctx.levels.retryPending().catch(() => {});
      const coinsTimer = ctx.coins.start();
      if (coinsTimer) timers.push(coinsTimer);
      // Item rewards owed (a failed grant, or a completion from before items) are granted by the same kind of timer.
ddiff --git a/server/quests/levels.js b/server/quests/levels.js
nnew file mode 100644
iindex 0000000..3443af2
---- /dev/null
++++ b/server/quests/levels.js
@@@ -0,0 +1,40 @@
++'use strict';
++const { serviceAuth } = require('openvibe-contracts');
++const { createClient } = require('openvibe-sdk/core');
++const { createLevelsClient } = require('openvibe-sdk/levels');
++const catalog = require('./catalog');
++const EXTRA_XP = 25;
++function createLevels({ config, s, fetchImpl = globalThis.fetch }) {
++    const tokens = serviceAuth.createTokenClient({ tokenUrl: `${config.networkInternalUrl}/oauth/token`, clientId: config.oauth.clientId,
++        clientSecret: config.oauth.clientSecret, audience: 'openvibe.network', scope: 'network.levels.award', fetchImpl });
++    const awards = createLevelsClient(createClient({ baseUrls: { network: config.networkInternalUrl }, getToken: () => tokens.getToken(), fetch: fetchImpl, retries: 0, timeoutMs: 5000 }));
++    let running = false;
++    async function settle(row) {
++        // Developer-defined badge quests cannot mint platform experience from arbitrary app events.
++        if (!catalog.byId(row.quest_id) && !/^daily-\d{4}-\d{2}-\d{2}$/.test(row.quest_id)) {
++            await s.db.exec("UPDATE quest_completions SET experience_state = 'skipped' WHERE id = $1", [row.id]); return false;
++        }
++        try { await awards.award({ subject: row.subject, amount: EXTRA_XP, reason: 'quest.completed', idempotency_key: row.id }); }
++        catch (e) {
++            if (e.status === 404 && e.code === 'levels.person_not_found') {
++                await s.db.exec("UPDATE quest_completions SET experience_state = 'skipped' WHERE id = $1", [row.id]); return false;
++            }
++            if (e.status !== 409 || e.code !== 'levels.duplicate') throw e;
++        }
++        await s.db.exec("UPDATE quest_completions SET experience_state = 'awarded' WHERE id = $1", [row.id]);
++        return true;
++    }
++    async function retryPending() {
++        if (running) return { awarded: 0 };
++        running = true;
++        let awarded = 0;
++        try {
++            const rows = await s.db.many("SELECT id, subject, quest_id FROM quest_completions WHERE experience_state = 'pending' ORDER BY completed_at LIMIT 50");
++            for (const row of rows) { try { if (await settle(row)) awarded++; } catch { /* durable pending row retries next tick; never log a credential */ } }
++        } finally { running = false; }
++        return { awarded };
++    }
++    function readClient(token) { return createLevelsClient(createClient({ baseUrls: { network: config.networkInternalUrl }, token: token || undefined, fetch: fetchImpl, retries: 0, timeoutMs: 5000 })); }
++    return { settle, retryPending, readClient };
++}
++module.exports = { createLevels, EXTRA_XP };
ddiff --git a/test/levels-page.test.js b/test/levels-page.test.js
nnew file mode 100644
iindex 0000000..415204a
---- /dev/null
++++ b/test/levels-page.test.js
@@@ -0,0 +1,25 @@
++'use strict';
++const assert = require('assert');
++const { boot, check, done } = require('./helpers/boot');
++(async () => {
++    const t = await boot();
++    const user = t.network.addUser('levels_page');
++    const entry = { subject: user.subject, username: 'levels_page', xp: 125, level: 2, rank: 1 };
++    t.ctx.levels.readClient = () => ({
++        board: async () => ({ all_time: { top: [entry], me: entry, around: [entry] }, week: { top: [entry], me: entry, around: [entry] } }),
++        get: async () => ({ level: 2, xp: 125, into: 25, span: 200, next_at: 300, rank: 1, recent: [{ name: 'Finished a quest', amount: 25, at: '2026-11-09T12:00:00Z' }] }),
++    });
++    try {
++        await check('public levels page shows boards and sign-in; signed-in page shows progress and named history', async () => {
++            let r = await t.get('/levels'); assert.equal(r.status, 200); assert(r.text.includes('All time')); assert(r.text.includes('Sign in to see your level'));
++            r = await t.get('/levels', { as: user }); assert.equal(r.status, 200);
++            assert(r.text.includes('Your level: 2')); assert(r.text.includes('Finished a quest')); assert(r.text.includes('value="25" max="200"'));
++            assert.equal(r.headers.get('cache-control'), 'private, no-store');
++        });
++        await check('Network outage gives a recoverable page', async () => {
++            t.ctx.levels.readClient = () => ({ board: async () => { throw new Error('down'); } });
++            const r = await t.get('/levels'); assert.equal(r.status, 503); assert(r.text.includes('temporarily unavailable'));
++        });
++    } finally { await t.close(); }
++    done();
++})().catch(() => process.exit(1));
ddiff --git a/test/levels.test.js b/test/levels.test.js
nnew file mode 100644
iindex 0000000..10c516c
---- /dev/null
++++ b/test/levels.test.js
@@@ -0,0 +1,24 @@
++'use strict';
++const assert = require('assert');
++const { createLevels } = require('../server/quests/levels');
++(async () => {
++    const state = new Map(); const sent = new Map(); let down = false;
++    const row = { id: 'qcp_probe', subject: 'usr_01JAB2C3D4E5F6G7H8J9K0MNP1', quest_id: 'follow-someone' };
++    const db = {
++        exec: async (_sql, [id]) => state.set(id, 'done'),
++        many: async () => state.has(row.id) ? [] : [row],
++    };
++    const fetchImpl = async (url, options) => {
++        if (String(url).endsWith('/oauth/token')) return new Response(JSON.stringify({ access_token: 'test-service-token', expires_in: 300 }), { status: 200 });
++        if (down) return new Response('{}', { status: 503 });
++        const body = JSON.parse(options.body); const duplicate = sent.has(body.idempotency_key);
++        if (!duplicate) sent.set(body.idempotency_key, body.amount);
++        return new Response(JSON.stringify(duplicate ? { code: 'levels.duplicate' } : { level: 1 }), { status: duplicate ? 409 : 201, headers: { 'content-type': 'application/json' } });
++    };
++    const levels = createLevels({ config: { networkInternalUrl: 'https://network.example', oauth: { clientId: 'quest', clientSecret: 'test-only' } }, s: { db }, fetchImpl });
++    down = true; await levels.retryPending(); assert(!state.has(row.id), 'outage leaves durable pending completion');
++    down = false; await levels.retryPending(); assert.equal(sent.get(row.id), 25); assert(state.has(row.id));
++    state.clear(); await levels.retryPending(); assert.equal(sent.size, 1, 'crash replay changes XP once'); assert(state.has(row.id), '409 settles the retry');
++    await levels.settle({ ...row, id: 'app-row', quest_id: 'app-custom' }); assert.equal(sent.size, 1, 'app events do not mint platform XP');
++    console.log('levels: completed quest awards 25 once; outages retry; duplicate refusal settles; app quests excluded');
++})().catch(e => { console.error(e); process.exitCode = 1; });