fix(hub): close seven bugs found in the refactor review

The PermissionRequest hook posted asks cut to the hub's field limits, so a signature covered less than Claude Code would run; it now posts nothing it cannot sign in full and leaves the decision to Claude Code with a reason on stderr. fields.seconds names the field the caller used in its error. Serving a stored page maps an OSError to 500 instead of a dropped connection. The natural-language line marks the register as seen before it builds the inbox, like the page does. do_POST runs every header guard (host, origin, client, content type, MCP) before it reads the body, so a refused request never costs its upload. The runner's reader closes stdout at EOF, because a close from the executing thread blocked on the buffer lock and could SIGPIPE a command still running. The page title counts only inbox items that are not snoozed.

Committed on the operator's word despite the gate: cost and time are estimates under 98 % other load and include eight new test cases.

🎯 Fix: 88 %
💥 Break: 3 %
💸 Cost: 106 %
⏱️ Time: 113 %
🛡️ Security: 100 %
🏆 Score: 71
🚦 Gate: ⛔ fix 88 % < 90; cost 106 % > 100, time 113 % > 100: ask the operator before the commit

```
/home/kevinveenbirkenbach/Repositories/github.com/kevinveenbirkenbach/skills/.worktrees/feature/kvb-hub
```

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

hub/kvb_hub/asking.py

@@ -55,7 +55,7 @@ class Asking:
         payload = decode(body)
         expect(payload, ("tool", *ASK_TEXTS, "timeout"))
         values = {name: bounded(payload, name, limit) for name, limit in ASK_TEXTS.items()}
-        lifetime = seconds(payload["timeout"], ASK_LIFETIME)
+        lifetime = seconds(payload, "timeout", ASK_LIFETIME)
         created = time.time()
         fields = {**values, "tool": field(payload, "tool").strip(), "status": "pending", "decided": None, "proof": None}
         record = self.asks.add({**fields, "created_ts": created, "expires": created + lifetime})
@@ -122,7 +122,7 @@ class Asking:
     def decision_wait(self, arguments: dict) -> dict:
         expect(arguments, ("id", "timeout_seconds"))
         decision_id = field(arguments, "id")
-        record = self.decisions.wait(decision_id, seconds(arguments["timeout_seconds"], WAIT_CAP))
+        record = self.decisions.wait(decision_id, seconds(arguments, "timeout_seconds", WAIT_CAP))
         if record is None:
             raise ToolError(f"no decision {decision_id}")
         return decision_state(record)