[kvlonge]

Parses Snowflake ALTER of 31 more object kinds into the typed AlterObject statement that #37 added. Until now they went through the opaque Command fallback.

• Routines: ALTER FUNCTION (UDF, external, service and data metric functions) and ALTER PROCEDURE. Both keep their argument types in a new AlterObject.arguments; a TABLE( ... ) argument is kept as a tuple.
• Other kinds: ALERT, AGENT, ARTIFACT REPOSITORY, COMPUTE POOL, CONTACT, DATASET, DBT PROJECT, DCM PROJECT, EVENT ROUTING TABLE, EXTERNAL AGENT, EXTERNAL TABLE, EXTERNAL VOLUME, FILE FORMAT, GATEWAY, GIT REPOSITORY, LISTING, MATERIALIZED VIEW, MODEL, MODEL MONITOR, NOTEBOOK, ONLINE FEATURE TABLE, PIPE, RESTRICTED SESSION SCOPE / RSS, SCHEMA, SERVICE, STAGE, STREAM, TYPE and VARIABLE.
• Layout: ALERT, ONLINE FEATURE TABLE, VARIABLE and FUNCTION live in parser/_helpers/ddl/snowflake_alter.rs. The other kinds are in a new snowflake_alter_resources.rs, which has one table of actions per kind and one shared SET/UNSET property parser. parse_alter is unchanged.
• Behaviour taken from the receipts, not the pages:
  • Property names are open (SET v1 = 'm' parses), but a SET of TAG or CONTACT pairs sets nothing else.
  • A stage path ends at whitespace, so @"s1 Q" is not one path.
  • An incomplete kind such as ALTER COMPUTE, ALTER VOLUME or ALTER EVENT TABLE is a syntax error.
  • Only external tables add partitions (ALTER TABLE … ADD PARTITION is refused for Snowflake).
  • An agent SETs one literal property at a time.
  • A restricted session scope adds and removes its body without AS.
  • A dataset version comes from a query.
• Tests: these extend tests/parser/test_snowflake_alter.rs.
• No catalogue changes. main 4a8656b is merged in.

Receipt harness: every form in the batch agrees with its receipts. That's 168 forms and 2,766 scored cases (ALERT/OFT/VARIABLE 19/226, FUNCTION 28/448, the 21 kinds of the first resource batch 92/1,666, and the 8 kinds of the second 29/426), and #37's 50 forms and 699 cases still agree. The only mismatches are unscored observe rows: missing-name cases with errno 1003 and no position (reviewed as semantic), and MATERIALIZED VIEW SET CONTACT, which Snowflake refuses.

Coverage diff: family <f> --json for all ten families. It compares the gate-profile checker of main 4a8656b with this branch's (6ca671e), over catalogue f139639 plus evidence a299d23:

ddl                  forms +67 -0   obligations +4594 -0
security_admin       forms +0 -0   obligations +8 -0
forms completed: +67 -0; obligations satisfied: +4602 -0

D122a floor: +67 forms against a floor of 67 (2% of 3,348), so this PR gates on form count. By kind, the gain is FUNCTION 14, VARIABLE 5, ALERT 3, COMPUTE POOL 3, DBT PROJECT 3, MODEL 3, ONLINE FEATURE TABLE 3, PROCEDURE 3, SCHEMA 3, SERVICE 3, and 1–2 each for the other kinds. Most of the remaining forms in these kinds already agree with every receipt, but still wait on observe rows or on receipts that lane A is capturing (packets d40/d40b).

Merge order: after #38 and #39.

[kvlonge]

Merge gate (D94):

• Head: 77c1a3a (tree 9724fb510ce9ef50ad53db43ede5888ad7b7802b), which merges main a2c64d6 (Fix parser gaps: empty arguments, type parameters, reserved names, anonymous procedures, tree findings #38 + Checker: never-submitted entries, readings in definition hashes, receipt account state #39).
• Command: CARGO_BUILD_JOBS=2 RUST_TEST_JOBS=1 RUST_TEST_THREADS=2 make check-merge RECORDER=0, run locally on that exact head. Exit code 0.
• Coverage diff with main a2c64d6's checker on the same catalogue and evidence tree: +69 forms, −0; +4,617 obligations, −0 (ddl +69 forms / +4,609 obligations, security_admin +8 obligations). That clears the D122 floor of 67 forms (2% of 3,348) by 2 forms.
• Hygiene scan of the outgoing diff: 0 hits. Author and committer are the noreply identity, with no trailers.
• Main has not moved since the gate, so the merge tree equals the gated tree.