把主線接進派工與注入（inkstone/ISEP#82）

- hooks.json     mainline-focus-guard 掛 Agent＋Task（派工的兩個入口都要守）；
                 SessionStart 多一條 `scripts/mainline refresh`（0.8s，不輪詢）
- hooks-inventory 54 支／71 條（當場數的）＋補人話一列；順手修掉上一版重複的那一行，
                 並把「指向空氣」那格的假警報寫清楚（countdown-milestone-refresh 在 scripts/）
- TESTING        A16（24 條離線）＋ A17（要網路的那半怎麼驗）
- plugin.json    描述數字對齊；版本不動，待總管定版

hooks/hooks.json

@@ -149,6 +149,10 @@
             "type": "command",
             "command": "${CLAUDE_PLUGIN_ROOT}/hooks/dispatch-format-guard.sh"
           },
+          {
+            "type": "command",
+            "command": "${CLAUDE_PLUGIN_ROOT}/hooks/mainline-focus-guard.sh"
+          },
           {
             "type": "command",
             "command": "${CLAUDE_PLUGIN_ROOT}/hooks/search-is-not-proof-guard.sh"
@@ -192,6 +196,10 @@
             "type": "command",
             "command": "${CLAUDE_PLUGIN_ROOT}/hooks/dispatch-format-guard.sh"
           },
+          {
+            "type": "command",
+            "command": "${CLAUDE_PLUGIN_ROOT}/hooks/mainline-focus-guard.sh"
+          },
           {
             "type": "command",
             "command": "${CLAUDE_PLUGIN_ROOT}/hooks/search-is-not-proof-guard.sh"
@@ -227,6 +235,10 @@
           {
             "type": "command",
             "command": "${CLAUDE_PLUGIN_ROOT}/scripts/countdown-milestone-refresh.sh"
+          },
+          {
+            "type": "command",
+            "command": "\"${CLAUDE_PLUGIN_ROOT}\"/scripts/mainline refresh"
           }
         ]
       }