Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@ROADMAP.md`:
- Line 11: Update the stale test-count mention in ROADMAP.md by replacing the
outdated "3,218 tests" reference with the current "3,223 tests" so the in-file
counts match the project summary; search for the literal "3,218 tests" and
change it to "3,223 tests" to keep the roadmap consistent.

In `@tests/conformance/manifest.json`:
- Around line 592-604: The spec_ref for the manifest entry with id
"ch07_exn_string" is incorrect (it currently reads "§7.2 Exn<E> handler — String
payload"); update the spec_ref field for "ch07_exn_string" to match the existing
mapping for the Exn handler (use "§7.4 Exn<E> handler — String payload") so it
is consistent with "ch07_exn_handler" and other exception-handler entries.

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@tests/conformance/manifest.json`:
- Line 603: Remove the unsupported "expected" field from the manifest entry
(delete the "expected": 10 line) so the manifest only contains recognized keys;
if you actually intend to enforce return-value checks, implement that in the
test harness (the conformance checker) rather than adding an "expected" metadata
field.

In `@tests/test_codegen.py`:
- Around line 3106-3160: Add a new unit test in tests/test_codegen.py that
exercises the empty-string Exn<String> case by invoking throw("") and asserting
behavior matches the other Exn<String> tests; mirror the patterns of
test_exn_string_throw_caught, test_exn_string_no_throw or
test_exn_string_handler_returns_string but use throw("") to cover the
zero-length payload branch and verify the runtime handles the ptr/len pair (len
== 0) correctly (assert expected return value or printed string as appropriate).

---

Duplicate comments:
In `@ROADMAP.md`:
- Line 224: Update the final summary string in ROADMAP.md that currently reads
"**3,223 tests**" (the instance in the closing summary paragraph) to the correct
updated total "**3,226 tests**" so it matches the other occurrences on Lines 11
and 182; locate the exact phrase "**630+ commits, 108 tagged releases, 3,223
tests, 96% coverage, 73 conformance programs, 30 examples, 13 spec chapters.**"
and replace only the test-count token to preserve the rest of the summary.

In `@tests/conformance/manifest.json`:
- Line 598: Update the spec_ref value that currently reads "§7.4 Exn<E> handler
— String payload" in the manifest entry so it matches the project's convention;
replace the leading "§7.4" with "Section 7.4" (i.e., make it "Section 7.4 Exn<E>
handler — String payload") to be consistent with the existing ch07_exn_handler
style.

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@ROADMAP.md`:
- Line 224: Update the inconsistent test count in the ROADMAP entry that
currently reads "**630+ commits, 108 tagged releases, 3,226 tests, 96% coverage,
73 conformance programs, 30 examples, 13 spec chapters.**" to match the rest of
the file and other occurrences ("3,227 tests"); locate and replace the "3,226
tests" token with "3,227 tests" so all instances are consistent with lines 11
and 182.

In `@tests/test_codegen.py`:
- Around line 3142-3160: Update the test_exn_string_handler_returns_string test
to include an ABI-level WAT assertion that pins the pair-tag encoding: after
compiling the source used in that test (same src and fn="test"), obtain the
emitted WAT (via the existing test helper used in this suite or by adding a
small helper similar to _run_io that returns WAT) and assert the WAT contains
the expected tag/result signature (e.g., the substring "result i32 i32" or the
exact pair-tag encoding your ABI uses). Keep the runtime assertion (assert
_run_io(src, fn="test") == "caught") and add only the additional WAT-level
assert so the test both verifies behavior and pins the codegen shape for
handle[Exn<String>] / result i32 i32.