fix: derive table aliases from relation paths

[collerek]

Table aliases are now derived from the relation path (alias_for("aseller__city")) instead of a global per-relation registry with "complex" aliases for duplicated paths. This fixes filters, exclude(), order_by(), fields() / exclude_fields(), values() and prefetch_related() on relation paths that end in the same relation, regardless of call order, and removes the in-place alias switching that let a derived queryset corrupt its source. Duplicate many-to-many paths that failed with "Ambiguous column name" now work, and select_related() on a through model raises a clear error.

Also fixes chained exclude() (based on #1826) and a select_related() crash when a column alias on the related model equals the relation name (based on #1829), both by @moneebullah25.

Closes #1816
Closes #1827

[codecov-commenter]

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[codspeed]

Merging this PR will improve performance by 23.64%

⚠️ 109 benchmarks spent significant time in system calls

System calls cannot be consistently instrumented, so they are not included in the measure, which understates the real cost. Please switch to the Walltime instrument to accurately measure system calls.

Measurement and system calls

• test_sum[500]
• test_avg[250]
• test_duplicate_relation_paths[100]
• test_duplicate_relation_paths[200]
• test_duplicate_relation_paths[50]
• test_exists[250]
• test_get_one_wide_model[500]
• test_max[250]
• test_select_related_nested_merge[10-10]
• test_select_related_nested_merge[20-10]
• …and 99 more

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 2 improved benchmarks
✅ 121 untouched benchmarks
🆕 3 new benchmarks

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
⚡ ⚠️	test_sum[500]	8 ms	6 ms	+34.49%
⚡ ⚠️	test_avg[250]	8.1 ms	7.1 ms	+13.67%
🆕 ⚠️	test_duplicate_relation_paths[100]	N/A	156.8 ms	N/A
🆕 ⚠️	test_duplicate_relation_paths[200]	N/A	299 ms	N/A
🆕 ⚠️	test_duplicate_relation_paths[50]	N/A	89.7 ms	N/A

Tip

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_{Comparing fix/path-based-table-aliases (ef52ba6) with master (1405d58)}