test(sdk): the pin was a permission, so give the premises a proof

The guard checked whether the installed SDK satisfied the pin. Nobody had
ever checked whether anyone had READ it. Those are different questions, and
the gap between them was a whole version range: pinned >=0.2.111,<0.3,
premises source-verified through 0.2.110, installed 0.2.120. Every build in
between was admissible and unexamined — `uv sync --upgrade` would have kept
806 tests green on an SDK no one had opened. Written red first: a guard
handed 0.2.140 returned it without complaint.

_VERIFIED_THROUGH is the ratchet. It records the newest build actually read
at source, and a newer one fails naming the five premises to re-check. The
pin is untouched and was never the defect — measurement dissolved the
premise that it needed lifting. It was not too narrow but too wide, and a
wider permission is not repaired by widening it further.

The premises themselves were prose the failure message recited. Nothing
tested them, so one that stopped being true would have surfaced on the one
live paid run (S10, D6). They are now a table introspected against the
installed package, with the printed prose derived from that same table so a
checked attribute cannot go unreported or a reported one unchecked. The
premise introspection structurally cannot see — that query() yields an
AssistantMessage then a closing ResultMessage — is named apart, and is the
honest reason the human reading still has to happen.

Value-proved, not merely named: disabling the ratchet reds 1 test, stubbing
the inventory to "no gaps" reds 3, re-hardcoding the prose reds 1, and
lowering _VERIFIED_THROUGH below the installed build reds the real
installed-version test rather than only a monkeypatched one.

0.2.139 read at source (0.2.120 -> 0.2.139, latest on PyPI today; STATE said
0.2.134, measured 08-09 and stale). The public query.py is byte-identical,
every premise field keeps its type and default, and the parser changes are
additive. One needed a look: 0.2.139 added a skills path defaulting
setting_sources to ["user", "project"], which would have undone the S10
isolation fix — it fires only on None, so the explicit [] is out of reach.
Prose carrying stale version claims moved with the reading, never ahead of
it: each was re-verified at 0.2.139 before being restated.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014dKDjVG7qrBh9NkAAxutqN

tests/test_sdk_isolation.py

@@ -2,7 +2,7 @@
 
 The S10 live run leaked the operator's Claude Code configuration into every
 spawned CLI session: ``ClaudeAgentOptions.setting_sources`` defaults to
-``None``, which loads ALL filesystem settings (verified against SDK 0.2.110)
+``None``, which loads ALL filesystem settings (verified against SDK 0.2.139)
 — session-start hooks injected STATE.md into the model's context, every reply
 opened with a mandated confirmation line (so a reply was NEVER pure JSON),
 and each call paid ~10-15k uncached context tokens. ``[]`` is the SDK's
@@ -49,11 +49,13 @@ class TestBuildCallOptions:
     def test_the_system_prompt_is_not_the_claude_code_preset(self) -> None:
         # Pins the OPTION value against the Claude Code preset. That None
         # reaches the spawned CLI as --system-prompt "" was verified by
-        # READING subprocess_cli.py (0.2.110–0.2.120) — this test does NOT
+        # READING subprocess_cli.py (0.2.110–0.2.139, re-read at 0.2.139:
+        # `system_prompt is None` still serializes to `--system-prompt ""`)
+        # — this test does NOT
         # bind that transport serialization; doing so would couple the suite
         # to SDK-private API (the F11 fragility this repo retired).
         #
-        # HONEST LIMIT (measured, 0.2.120): `system_prompt=None` is NOT
+        # HONEST LIMIT (measured, re-measured at 0.2.139): `system_prompt=None` is NOT
         # distinguishable from leaving the field untouched — the SDK default
         # is None too, so deleting `system_prompt=None` from build_call_options
         # left the old `is None` assertion GREEN. It pinned the SDK's default,