Centralize wire-protocol namespace validation tests (TEST_COVERAGE.md §19)

[imforster]

Problem

TEST_COVERAGE.md §19 specifies that wire-protocol namespace validation should have a single centralized test site, with each command running only one representative case. Currently every command (compact, drop, count, aggregate, renameCollection, insert, and others) duplicates a full 15-case BSON-type rejection matrix for the collection-name field, asserting INVALID_NAMESPACE_ERROR.

What to do

1. Create the centralized namespace validation test site (location TBD per §19).
2. Trim each command's collection-name rejection matrix to 1-2 representative cases that delegate to the central site.

Scope

Commands known to duplicate the matrix:

• insert (test_insert_argument_handling.py:21-122)
• compact
• drop
• count
• aggregate
• renameCollection
• Others

Context

Identified during PR #597 review. Left as-is in that PR to stay consistent with sibling commands. Should be addressed as a single sweep across all commands.

[documentdb-triage-tool]

🤖 Auto-triaged by documentdb-triage-tool.

Applied: compatibility test, enhancement
Project fields suggested: Component test-coverage · Priority P3 · Effort L · Status Triage
Confidence: 0.85 (llm)

Reasoning

LLM: Test deduplication/refactor across multiple command test files with no functional bug or blocking issue — purely a polish/maintainability sweep.

If a label is wrong, remove it manually and ping @patty-chow so the rules can be tuned. The bot will not re-label items that already have component labels.