Fix pg_class join style and keep regression coverage

[iBarBuba]

What

• Refactored sequence and index query construction into dedicated builder methods:
  • Dump::build_sequences_standalone_query in app/src/dump/core.rs
  • Table::build_indexes_bulk_query in app/src/dump/table.rs
• Kept the pg_description joins scoped to relation comments by filtering on:
  • pg_description.classoid = 'pg_class'::regclass
  • pg_description.objsubid = 0
• Added regression tests proving both query builders include the pg_class classoid filter:
  • build_sequences_standalone_query_filters_by_pg_class
  • build_indexes_bulk_query_filters_by_pg_class
• Normalized SQL formatting in the new helper query strings.

Why

Existing database objects can appear in diffs when comment lookups join pg_description
without narrowing the catalog class. The fix keeps sequence and index comments tied to
pg_class entries, avoiding accidental matches from other catalogs that can reuse the
same object identifier value.

Validation

• cargo fmt --manifest-path app/Cargo.toml
• cargo test --manifest-path app/Cargo.toml (801 passed, 0 failed)
• git diff --check (clean)

Links

• PR: Fix pg_class join style and keep regression coverage #177
• Issue: Existing tables can be falsely diffed as missing columns due to incomplete pg_description joins #176

Closes #176

[Copilot]

Pull request overview

This PR addresses false-positive diffs caused by under-constrained pg_description joins by ensuring classoid = 'pg_class'::regclass is included where pg_class-backed objects (tables, columns, indexes, sequences, views) are joined for comments. It also refactors several SQL query strings into dedicated builder functions and adds regression tests to ensure the classoid filters remain present.

Changes:

• Add pg_description.classoid = 'pg_class'::regclass predicates to relevant comment joins (tables, table columns, indexes, sequences, views, view columns).
• Refactor standalone/bulk dump query construction into build_*_query helper functions.
• Add unit tests asserting the pg_class classoid filter is included in the generated queries.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
app/src/dump/table.rs	Adds pg_class classoid filter for column/index comment joins; extracts index bulk query builder; adds regression tests.
app/src/dump/core.rs	Extracts table/view/sequence query builders and adds pg_class classoid filters for object/column comment joins; adds regression tests.

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[nettrash]

Issue is real.
Fix is correct.

[nettrash]

@iBarBuba Please add this information to CHANGELOG. v1.0.19

[iBarBuba]

@iBarBuba Please add this information to CHANGELOG. v1.0.19

@nettrash Added ✅

• Updated CHANGELOG with v1.0.19 entry (no date, as requested), under "Bug fixes", including PR Fix pg_class join style and keep regression coverage #177 query refactors, pg_description classoid filtering, and regression tests for both builders.