Add Mastermind and Hangman single-player games

- Mastermind: 4-color sequence, 10 tries, black/white peg feedback
- Hangman: 6 lives, progressive letter reveal, 10-word vocabulary
- Both available in BBS (telnet) and web (WML/XHTML) sides
- Shared sp_games persistence, scores table integration
- Updated games index and menu navigation

public_html/games/hangman.php

@@ -0,0 +1,98 @@
+<?php
+// Single player: Hangman. Guess the word, 6 lives.
+// State persisted in sp_games (game='hangman').
+require_once __DIR__ . '/../lib/bootstrap.php';
+$me = require_login();
+
+const H_WORDS = ['python', 'bbs', 'telnet', 'wml', 'matrix', 'linux', 'mastermind', 'screens', 'forum', 'games'];
+const H_MAX_LIVES = 6;
+
+function h_load(int $uid): ?array {
+    $s = db()->prepare("SELECT * FROM sp_games WHERE user_id=? AND game='hangman'
+                        AND status='active' ORDER BY id DESC LIMIT 1");
+    $s->execute([$uid]);
+    return $s->fetch() ?: null;
+}
+function h_new(int $uid): array {
+    $word = H_WORDS[array_rand(H_WORDS)];
+    $st = json_encode(['word' => $word, 'used' => [], 'lives' => H_MAX_LIVES]);
+    $now = time();
+    db()->prepare("INSERT INTO sp_games (game,user_id,state,created_at,updated_at)
+                   VALUES ('hangman',?,?,?,?)")->execute([$uid, $st, $now, $now]);
+    return h_load($uid);
+}
+
+$msg = ''; $done = false;
+$g = h_load((int)$me['id']);
+
+if ($_SERVER['REQUEST_METHOD'] === 'POST') {
+    require_csrf();
+    $act = $_POST['act'] ?? '';
+    if ($act === 'new') {
+        if ($g) db()->prepare("UPDATE sp_games SET status='abandoned' WHERE id=?")->execute([$g['id']]);
+        $g = h_new((int)$me['id']);
+        $msg = 'New game! I have chosen a word. Guess letters one at a time.';
+    } else {
+        if (!$g) $g = h_new((int)$me['id']);
+        $st = json_decode($g['state'], true);
+        $letter = strtolower((string)($_POST['letter'] ?? ''));
+        if (strlen($letter) !== 1 || !ctype_alpha($letter)) {
+            $msg = 'Please enter a single letter a-z.';
+        } elseif (in_array($letter, $st['used'], true)) {
+            $msg = 'You have already used that letter.';
+        } else {
+            $st['used'][] = $letter;
+            if (in_array($letter, str_split($st['word']), true)) {
+                $msg = 'Good! ' . $letter . ' is in the word.';
+            } else {
+                $st['lives']--;
+                $msg = $letter . ' is not in the word.';
+            }
+            // Check win/loss
+            $word_letters = array_diff(str_split($st['word']), $st['used']);
+            if (empty($word_letters)) {
+                $score = max(1, 50 - (H_MAX_LIVES - $st['lives']) * 5);
+                db()->prepare("UPDATE sp_games SET status='won', state=?, updated_at=? WHERE id=?")
+                    ->execute([json_encode($st), time(), $g['id']]);
+                db()->prepare("INSERT INTO scores (game,user_id,score,detail,created_at)
+                               VALUES ('hangman',?,?,?,?)")
+                    ->execute([$me['id'], $score, $st['lives'] . ' lives left', time()]);
+                $msg = "Yay! You guessed the word {$st['word']}! Score: $score";
+                $done = true; $g = null;
+            } elseif ($st['lives'] <= 0) {
+                db()->prepare("UPDATE sp_games SET status='lost', state=?, updated_at=? WHERE id=?")
+                    ->execute([json_encode($st), time(), $g['id']]);
+                $msg = "You died! The word was {$st['word']}.";
+                $done = true; $g = null;
+            } else {
+                db()->prepare("UPDATE sp_games SET state=?, updated_at=? WHERE id=?")
+                    ->execute([json_encode($st), time(), $g['id']]);
+                $g['state'] = json_encode($st);
+            }
+        }
+    }
+}
+
+page_start('Hangman', ['back' => '/games.php']);
+if ($msg) p_para($msg);
+if ($g) {
+    $st = json_decode($g['state'], true);
+    $display = '';
+    foreach (str_split($st['word']) as $ch) {
+        $display .= (in_array($ch, $st['used'], true) ? $ch : '-') . ' ';
+    }
+    p_para('Word: ' . trim($display));
+    p_para('Lives left: ' . $st['lives']);
+    if ($st['used']) p_para('Used: ' . implode(', ', $st['used']));
+    p_form('/games/hangman.php', [
+        ['name' => 'letter', 'label' => 'Guess a letter', 'maxlength' => 1,
+         'format' => '*A'],
+    ], 'Guess');
+} else {
+    if (!$done) p_para('Guess the word one letter at a time. You have 6 lives.');
+}
+p_form('/games/hangman.php', [
+    ['name' => 'act', 'type' => 'hidden', 'value' => 'new'],
+], $g ? 'Restart' : 'New game');
+p_links([['/games/scores.php', 'High scores', ['g' => 'hangman']], ['/games.php', 'Games']]);
+page_end();