Merge remote-tracking branch 'gh/main' into fix/help-keys-checks

# Conflicts:
#	context/test-evidence/clients.md
#	context/test-evidence/protocol.md

context/test-evidence/protocol.md

@@ -557,7 +557,7 @@ the evidence that nothing was relying on the permissive parse.
 
 ### render::tests::two_runs_under_two_headers_of_one_name_are_two_runs
 
-### render::tests::the_two_headers_are_equal_as_values_so_comparing_cat_and_name_cannot_split_them
+### render::tests::the_two_headers_are_equal_as_values_so_comparing_them_cannot_split_them
 
 improvise-h0iv. `group_runs` coalesced adjacent positions by group **name**, so
 two runs under two different headers sharing a name read as one and both front
@@ -571,10 +571,12 @@ and nothing ungrouped between the runs. Before the fix it returns
 at the precondition rather than pass with a single run.
 
 The second test exists because the ticket proposed the wrong fix and a reader
-will propose it again. h0iv says `FrameGroup` carries `cat` and "comparing the
-pair would fix it" — but its own reachability case is a single category nested
-under an outer one, so both headers are `(Month, Q1)`, equal as values. The test
-asserts that equality directly. What actually separates them is that they are
+will propose it again. h0iv said `FrameGroup` carried `cat` and that "comparing
+the pair would fix it". But its own reachability case is a single category
+nested under an outer one, so both headers are `(Month, Q1)`, equal as values.
+The test asserts that equality directly. Since improvise-7xyx removed
+`FrameGroup::cat`, it asserts equality of the whole header, which is stronger:
+no field-wise comparison can separate two equal values. What actually separates them is that they are
 two distinct entries in `self.entries`, which `std::ptr::eq` on the borrowed
 header states exactly.
 
@@ -970,6 +972,27 @@ give `None` and fail. Asserting only that `"command"` survived would pass under
 either behaviour, which is what the old spelling amounted to for the cleared
 key.
 
+### render::tests::a_cell_equals_another_exactly_when_the_wire_cannot_tell_them_apart
+
+`CellDisplay`'s equality is what the grid diff and the seed property run on
+(improvise-4w09). It compares `value` by `same_on_the_wire`: bits, except that
+every NaN is equal. It pins both clauses, since `a_grid_holding_nan_quiesces`
+can see only one of them. That test compares a NaN with its own bits,
+in-process.
+
+- A NaN with the sign bit set, the shape `0.0 / 0.0` produces on x86, equals
+  `f64::NAN`, the shape `parse_nonfinite("nan")` gives a client. Both go out as
+  the one token `"nan"`.
+- `0.0` differs from `-0.0`: serde_json writes them as `0.0` and `-0.0`, so a
+  change between them is real and must be sent.
+- `Number(7.0)` differs from `Text("7")`, and a value differs from none.
+
+**Faults injected:**
+- `f64 ==` (the pre-fix semantics). Fails at the NaN case.
+- Bit equality only. Fails at the NaN case, while `a_grid_holding_nan_quiesces`
+  **passes**, which is why this test exists.
+- `f64 ==` plus the NaN clause. Fails at the `0.0`/`-0.0` case.
+
 ### vocabulary_is_composed::a_variant_named_only_in_a_comment_or_string_is_not_composed
 
 improvise-c7mu, found by the post-merge review of PR #160. `constructed_in` ran
@@ -1030,6 +1053,54 @@ A field added to an existing variant is caught too, but not in isolation,
 because every constructor of that variant also fails. Reverted with
 `git restore`.
 
+### source_scan::tests::a_test_only_item_hides_nothing_after_it
+
+improvise-59q8, found by the PR #172 review. The scanner's line-based
+`strip_test_items` looked for `}` at the attribute's indentation, or for an item
+line ending in `;`. So three shapes were never bounded, and it dropped
+**everything to the end of the file**:
+- a test-only `const … = &[\n … \n];`;
+- a `#[cfg(test)] let x = foo(\n 1,\n);` statement;
+- a one-line `#[cfg(test)] use foo::bar;`, where the attribute's own line is
+  also the item line.
+
+In `vocabulary_is_complete` that silently hides every effect after such an
+item. Each shape is a case here, asserting that the production code after it
+(`Hidden1`, `Visible`) survives. Against the line scan all three failed; the
+first printed `"impl X {\n"` and nothing else. They now pass because items are
+bounded by balanced brackets on the blanked code.
+`an_unbounded_test_only_item_is_refused_not_swallowed` pins the other half of
+the acceptance criteria: an item that cannot be bounded panics instead of
+consuming the rest of the file. Against the line scan it failed, because
+nothing panicked.
+
+### source_scan::tests::a_test_only_cfg_is_recognised_whatever_its_spelling
+
+improvise-59q8, the other direction: test code counted as production, which
+makes `vocabulary_is_composed` weaker. `cfg(all(test, not(target_arch =
+"wasm32")))` was kept because the old rule rejected any line containing
+`not(`. A leading `#![cfg(test)]` was kept because only `#[cfg(` was
+recognised. An attribute split across lines was not seen at all. All three
+failed against the old scanner. The predicate is now parsed and evaluated in
+three-valued logic (`context/code/protocol.md` §2). The controls
+(`cfg(not(test))`, `cfg(any(test, feature = "serde"))` and `cfg(target_arch =
+…)`) must stay production, so a scanner that dropped every `cfg` item could
+not pass.
+
+A consequence to know about: `cfg(any(test, feature = "x"))` for an ordinary
+feature is now production. Only `feature = "test-support"`, the one test
+feature this repo has, counts as a test build.
+`test_only_items_and_modules_are_not_production` was updated to that spelling.
+
+### source_scan::tests::a_c_string_literal_is_blanked
+
+improvise-59q8's minor case. In `cr#"x" Command::InRawC(2) "y"#` the `r` has a
+word character before it, so the literal was lexed as two ordinary strings,
+and the text between the inner quotes leaked. It failed as
+`InRawC survived`. `c"…"` and `cr#"…"#` are now literals. A first version of
+this test used a C string with no inner quotes and passed against the bug,
+because the ordinary lexing happened to blank it too.
+
 ### help::tests::no_help_row_spells_a_key_by_hand
 
 improvise-wk18. The help pages had one kind of row whose keys the keymap never