feat(font+sys): 字库内存纪律(agent-215)+sysui接管launcher监管(agent-216)

215: meow_font.c 流式分块解码(gbk峰值40→23.5MB, 逐字节校验一致) + 多字体槽5→4+16MB驻留预算; 量化: gbk稳态驻留17.3MB vs common 4.2MB(OOM主因); meow_font.a→67113c03 meow_ui.a→223d5401
216: bootmenu让位(sysui在则start launcher让位, 不在则exec兜底) + S70预置launcher.conf enabled=1(+旧设备升级迁移); launcher崩溃可自动拉起; bootmenu 4441822d / S70 e435affc / S90 e0ace111
216注: S70早启动与选单共存为真机重点观察项

font/test_budget.c

@@ -0,0 +1,39 @@
+/*
+ * test_budget.c — 宿主校验 meow_font_config_multifont 的「打包面内存预算」：
+ *   slot0=common（≈4.2MiB）+ 给 CJK 类别装 gbk（≈16.6MiB）→ 合计 > MEOW_MULTIFONT_MEM_BUDGET
+ *   → gbk 应被拒绝（distinct=1，truncated=1），防止大字库 + 多字体双驻留 OOM。
+ * 用法：gcc -I. test_budget.c meow_font.c -lz -o test_budget
+ *       ./test_budget <common.png> <common.idx> <gbk.png> <gbk.idx>
+ */
+#include "meow_font.h"
+#include <stdio.h>
+#include <string.h>
+
+static int g_fail = 0;
+#define CHECK(cond, msg) do { \
+    if (!(cond)) { g_fail++; fprintf(stderr, "FAIL: %s\n", msg); } \
+    else printf("ok  : %s\n", msg); \
+} while (0)
+
+int main(int argc, char **argv) {
+    if (argc < 5) { fprintf(stderr, "usage: %s <common.png> <common.idx> <gbk.png> <gbk.idx>\n", argv[0]); return 2; }
+    int r = meow_font_load(argv[1], argv[2]);            /* slot0 = common */
+    CHECK(r == 0, "load slot0 common");
+    meow_font_class_cfg cfg[MEOW_FCLS_COUNT];
+    memset(cfg, 0, sizeof cfg);
+    cfg[MEOW_FCLS_CJK].png = argv[3];                    /* CJK 类别 → gbk 大字库 */
+    cfg[MEOW_FCLS_CJK].idx = argv[4];
+    int distinct = 0, truncated = 0;
+    r = meow_font_config_multifont(1, argv[1], argv[2], cfg, &distinct, &truncated);
+    CHECK(r == 0, "config_multifont ok");
+    printf("  distinct=%d truncated=%d\n", distinct, truncated);
+    /* slot0 common 4.2MiB + gbk 16.6MiB = 20.8MiB > 16MiB 预算 → gbk 被拒 → distinct 仅全局 */
+    CHECK(distinct == 1, "distinct==1 (gbk rejected by MEM_BUDGET)");
+    CHECK(truncated == 1, "truncated==1 (budget exceeded -> class fell back to global)");
+    /* gbk 槽应未驻留：distinct==1（仅全局 common）即证明 gbk 未被 commit；
+     * 注意 common 4k 亦含「中」，故不能以 has_glyph(中)==0 断言——改以「common 仍在」佐证。 */
+    CHECK(meow_font_has_glyph('A') == 1, "has_glyph(A)==1 (common still there)");
+    meow_font_unload();
+    printf("\nRESULT: %s\n", g_fail ? "FAIL" : "PASS");
+    return g_fail ? 1 : 0;
+}