Merge authoritative main into the task branch

Why: include the current integration baseline before verification.

Evidence: fetched origin/main=59cbf1109634b66c88f5b1702f330cd738aa75ef.

Impact: integrate upstream changes without rewriting task history.

Refs: task-sync

DESIGN.md

@@ -36,6 +36,13 @@ Agent-System-Dev 是桌面优先、Web 兼容的 AI 工作台。界面应**冷
 | `--bg-hover` | `rgba(255,255,255,.05)` | `rgba(13,13,13,.05)` | 通用悬停 |
 | `--bg-active` | `rgba(255,255,255,.10)` | `rgba(13,13,13,.08)` | 选中态 |
 
+三栏工作台的顶栏与左栏使用独立导航骨架令牌：`--workbench-chrome`、
+`--workbench-chrome-text`、`--workbench-chrome-dim`、`--workbench-chrome-faint`、
+`--workbench-chrome-hover`、`--workbench-chrome-active`。浅色主题为近黑导航骨架，深色主题取面板阶梯，
+墨绿主题取海军蓝侧栏；反色创建按钮的 hover/分隔线使用
+`--workbench-chrome-inverse-hover` / `--workbench-chrome-inverse-border`。宿主组件只能消费这些令牌，
+不得用 `color-mix()`、rgba 或局部变量再次派生导航颜色。
+
 ### 2.2 边框（发丝三档）
 
 `--border-soft: rgba(255,255,255,.06)` / `--border: rgba(255,255,255,.10)` /

tests/test_task.py

@@ -24,7 +24,10 @@ class TaskLifecycleTests(unittest.TestCase):
         self.env.update({"GIT_CONFIG_NOSYSTEM": "1", "GIT_CONFIG_GLOBAL": "/dev/null",
                          "GIT_ALLOW_PROTOCOL": "file", "GIT_TERMINAL_PROMPT": "0",
                          "GIT_AUTHOR_NAME": "Lifecycle Test", "GIT_AUTHOR_EMAIL": "test@example.invalid",
-                         "GIT_COMMITTER_NAME": "Lifecycle Test", "GIT_COMMITTER_EMAIL": "test@example.invalid"})
+                         "GIT_COMMITTER_NAME": "Lifecycle Test", "GIT_COMMITTER_EMAIL": "test@example.invalid",
+                         "GIT_CONFIG_COUNT": "2", "GIT_CONFIG_KEY_0": "gc.auto",
+                         "GIT_CONFIG_VALUE_0": "0", "GIT_CONFIG_KEY_1": "maintenance.auto",
+                         "GIT_CONFIG_VALUE_1": "false"})
         for key in ("GIT_DIR", "GIT_WORK_TREE", "GIT_INDEX_FILE", "GITEA_TOKEN", "PRECHECK_RECEIPT",
                     "TASK_PARENT_BRANCH", "TASK_PARENT_PR", "FORCE_ABANDON", "TASK_TARGET_BRANCH",
                     "TASK_WORK_MODE", "VALIDATE_RECEIPT_PURPOSE"):