Seven inline comments, all valid; two are real bugs.

parser/directive.go
  - End-of-loop guard in ExtractInlineRenames: a `pending` directive
    whose target line never arrived (statement body ran out) is now
    appended to Unsupported instead of being silently dropped.
    (Copilot #1.)
  - leadingBacktickedIdent comment rewritten: previous wording had
    curly quotes ("…" instead of `…`) and didn't explain MySQL's
    backtick-doubling escape. New comment is precise: doubled
    backticks remain unsupported; the regex correctly rejects them
    so the validator surfaces "malformed directive". (Copilot #2, #3.)

diff/rename.go
  - applyTableRenames / applyColumnRenames / applyIndexRenames now
    short-circuit when RenameFrom equals the desired name. This
    avoids generating `ALTER TABLE x RENAME TO x` (rejected on some
    MySQL versions, no-op on others) for what is almost always a
    user typo. (Copilot #5, #6, #7.)
  - rewriteConstraintColumnRefs: PRIMARY KEY column lists in
    current.Constraints are rewritten old → new alongside the index
    and FK rewrites, so a renamed-PK column doesn't surface as
    DROP+ADD PRIMARY KEY in diffConstraints. CHECK constraints are
    deliberately skipped — their Definition is a free-form
    expression and rewriting it requires a full SQL parser.
    (Copilot #4.)

diff/tables.go
  - Calls rewriteConstraintColumnRefs after applyColumnRenames,
    alongside the existing index / FK rewrites.

Tests
  - parser/directive_test.go: TestExtractInlineRenamesTrailingPendingUnsupported
    covers the end-of-loop pending path.
  - diff/rename_test.go: TestDiffRenameSelfRenameIsNoOp covers the
    table / column / index self-rename guards in one shot.
    TestDiffRenameColumnAlsoRewritesPKConstraint covers the new PK
    rewrite end-to-end (renames `users.old_id` → `users.id` and
    asserts no DROP/ADD PRIMARY KEY appears).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Two inline comments, both real bugs.

parser/directive.go
  - ExtractStmtRenameFrom now also skips `#` line comments and
    single-line `/* … */` block comments in the leading block.
    Previously it stopped at the first non-`--` line, so a stray
    `# header` or `/* generated */` between such a comment and
    `-- myschema:renamed-from` defeated the scan: the validator
    saw the directive as known, but the extractor never reached it,
    and the rename silently degraded into DROP+CREATE. Mirrors the
    same skip logic in ExtractInlineRenames. (Copilot #1.)

diff/rename.go + diff/tables.go
  - rewriteFKColumnRefs() now takes (db, name) and, for any FK
    whose (RefDB, RefTable) matches that table (i.e. self-
    referential), rewrites RefCols too. The cross-table pass in
    DiffTables explicitly skips the renamed table itself, so without
    this self-ref handling a `users.parent_id REFERENCES users(id)`
    FK would diff as DROP+ADD after renaming `users.id`. (Copilot #2.)
  - diffTable threads `current.Database, current.Name` into the call.

Tests
  - parser/directive_test.go: TestExtractStmtRenameFromSkipsLeadingHashAndBlockComments
    covers `#` and `/* … */` lines preceding the directive in the
    leading block.
  - diff/rename_test.go: TestDiffRenameColumnAlsoRewritesSelfReferentialFK
    covers the self-ref RefCols rewrite end-to-end (renames
    users.id → users.user_id with a self-referential
    fk_parent(parent_id) → users(id), asserts no DROP/ADD on
    fk_parent).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

#1 Pin the RANGE COLUMNS REORGANIZE end-to-end. The plan-only
   fixture (partition_value_change_reorganize_range_columns.yml)
   covered the generator side, but nothing confirmed MySQL accepts
   `REORGANIZE PARTITION ... INTO (...)` with tuple boundaries or
   that the rewritten boundaries round-trip cleanly. Add the
   matching apply / verify_no_drift fixture.

#2 The case-only partition-name no-op already has a regression test
   (`partition_name_case_only_diff_no_op.yml`, commit 4c6998f).

#3 Pin the per-partition *option*-only diff (here: COMMENT-only)
   end-to-end. partitionDefEqual delegates to
   `parser.FormatPartitionDefinition`, which preserves COMMENT /
   MAX_ROWS / TABLESPACE / etc., so any byte-different definition
   already routed through the REORGANIZE branch — but no fixture
   pinned that MySQL accepts the generated statement or that the
   rewritten options round-trip. New apply fixture
   `partition_per_partition_option_change_reorganize.yml` covers
   both. LIST avoids the RANGE upper-bound cascade so the
   REORGANIZE only touches the one slot whose option actually
   changed.

#4 / #5 / #6 Widen the Coverage / Not-yet-implemented sections of
   AGENTS.md (in scope + v1 cuts) and the TODO.md "Already shipped"
   block from "pure value-change (same names, only `VALUES`
   differs)" to "per-partition definition rewrite ... when both
   sides have the same partition names in the same order — covers
   `VALUES …` boundary tweaks plus COMMENT / MAX_ROWS /
   TABLESPACE / other per-partition option changes that round-trip
   through vitess's PartitionDefinition formatter". Brings the
   docs in line with what diffPartitions actually does (and with
   what CAVEATS.md "Per-partition definition change" already
   describes).

#7 Fix the misleading comment in partitionNameListEqual.
   `parser.NormalizePartitionOption` only lower-cases function /
   column-reference identifiers inside the partition expression —
   it does NOT lower-case partition names. The case-insensitive
   `EqualFold` here is needed precisely because the round-trip
   preserves whatever case the user wrote on the partition name.

Round 1 review on PR #75 caught eight issues; this commit addresses
all of them.

1. (review #1) loadPreSQL treated any non-empty PreSQL string as
   "set", including whitespace-only values. Whitespace-only env
   var (`MYSCHEMA_PRE_SQL=`) would trigger the mutually-exclusive
   error against a legitimate --pre-sql-file, and skip the no-op
   short-circuit. Fix: TrimSpace both fields before deciding "set".

2. (review #2) loadPreSQL read --pre-sql-file with os.ReadFile,
   which doesn't support the repo's existing `-` for stdin
   convention used by parser.ReadSQLFile (the desired-SQL file
   args already accept it). Fix: route through parser.ReadSQLFile
   so `--pre-sql-file=-` works.

3. (review #3 + #4) runPreSQL was invoked AFTER connect(), so
   flag-validation errors (both flags set, missing file) could be
   masked by a downstream connection failure, and the client
   opened a DB connection it then threw away. Split into:
   - loadPreSQL: validate / read, no DB contact (called BEFORE connect)
   - execPreSQL: run on conn (called AFTER connect)
   apply.go and plan.go updated accordingly.

4. CLI-level mutual exclusion: tag both PreSQL and PreSQLFile with
   kong's `xor:"pre-sql"` so kong rejects the both-set case at
   parse time before our code sees it. The runtime check in
   loadPreSQL stays in place for programmatic API callers
   (Apply / Plan invoked from Go without going through kong).

5. (review #5 / #6 / #7 / #8) Test reshuffle. The original
   suite over-relied on success-only smoke tests that would have
   silently passed even if pre-SQL were skipped:
   - TestApply_PreSQLString and TestApply_PreSQLMultiStatement
     only checked NoError.
   - TestApply_PreSQLAppliesToSession claimed to be the
     "strongest behavioural pin" but probed nothing — the
     connection it would have probed is closed by Apply's defer.
   - TestPlan_PreSQLString same issue.
   Fix: load-bearing pins now feed INVALID pre-SQL and assert
   the apply / plan aborts with a wrapped "pre-sql" error
   containing the exact failing piece. The multi-statement
   split test now uses a payload with an invalid SECOND piece
   and asserts the error references that piece exactly (proves
   the split happened — without splitting, the driver would
   reject the whole concatenated string with a different error).

6. YAML migration: the new harness field `pre_sql` lets
   inline-payload tests live as testdata/apply/pre_sql_*.yml and
   testdata/plan/pre_sql_*.yml fixtures (3 + 1 = 4 new fixtures).
   File-related and programmatic-API tests stay in Go because
   the YAML harness has no `pre_sql_file` field (would need
   fixture-relative path handling, out of scope).

Coverage is unchanged at the package level; loadPreSQL stays at
100% and execPreSQL is exercised by all the real-execution paths.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>