fix(#20): heid-bug-hunt fixups — probe ConnectFailed + adapter finite-PAD (slice-3)

The slice-3 heid-bug-hunt panel (3/3) caught a real regression the cutover
introduced, plus a chokepoint-invariant gap:

- ConnectFailed escaped both rewired CLI probes. When --set-persona-pad and
  --seed-first-message moved off raw httpx onto the wt adapter, transport failures
  changed class: the SDK normalizes any pre-response transport error to
  worldtree_sdk.ConnectFailed (request.py), a WorldtreeError (not ApiError), so it
  passed the adapter unmapped AND the probes' httpx-only except tuples → an uncaught
  traceback instead of the graceful [network_error] exit 21. _amain (slice-2) already
  handled it; the probes lagged. Fix: add ConnectFailed to both probe except tuples
  (mirrors _amain). Live-verified at a refused host → [network_error] exit 21.

- Finite-PAD enforced only at the CLI, not the adapter chokepoint. wt.set_persona_state
  delegated finiteness to the caller (documented), so a direct/non-CLI caller passing
  nan/inf got a raw SDK ConfigurationError. Fix: assert finiteness in the adapter
  precondition (consistent with its other precondition asserts) so the invariant holds
  at the chokepoint in ratatoskr's own terms; the CLI pre-check stays for the friendly
  usage error.

Triaged-and-declined (all correct per the panel + Heid's source-check): the deleted
sessions.py exports (intended no-shim cutover, zero un-migrated importers), the
session["session_id"] index (accept-known-risk, matches --new), and Regin's "web
indefinite block" (refuted — the seed is asyncio.wait_for-bounded). The concurrent
heid-code-review panel returned zero drift, no code change.

TDD: 3 RED tests (both probes' ConnectFailed → exit 21; adapter nan/inf/-inf →
AssertionError, never reaches the SDK) → GREEN. Suite 469; ruff clean; mypy no new errors.

tests/test_wt.py

@@ -482,6 +482,16 @@ class TestSetPersonaState:
             await set_persona_state(_wt(fake), "s", pleasure=0.0, arousal=0.0, dominance=0.0)
         assert ei.value.status == 500
 
+    async def test_non_finite_pad_rejected_at_the_chokepoint(self) -> None:
+        # The finite-PAD invariant is enforced at the adapter (not only the CLI): a
+        # non-finite axis would serialize to null and corrupt the injection, so a
+        # direct caller is rejected pre-SDK — never a leaked SDK ConfigurationError.
+        fake = _FakeSessions(result=None)
+        for bad in (float("nan"), float("inf"), float("-inf")):
+            with pytest.raises(AssertionError):
+                await set_persona_state(_wt(fake), "s", pleasure=bad, arousal=0.0, dominance=0.0)
+        assert fake.calls == []  # never reached the SDK
+
 
 class TestWriteAuthoredHistory:
     """slice-3: write_authored_history → SDK sessions.write_history. Builds the