fix(ci): quiet Rust test output

[lovasoa]

Problem

The PostgreSQL matrix failure in the referenced job is difficult to diagnose because the failure output contains every passing test and a very large repeated SQL error.

Root Cause

stop_at_first_error logged every DbItem::Error with the full anyhow chain at error level. The same error was then handled downstream. For error_too_many_nested_inclusions.sql, each recursive sqlpage.run_sql context was included repeatedly, producing a huge target=sqlpage::webserver::database::execute_queries line. The aggregate SQL-file test attached all captured logs to one failure.

Recursive errors were also wrapped again by each parent run_sql call and statement-position formatter, so development error pages repeated the same context.

Fix

• Stop logging the database error redundantly in stop_at_first_error; downstream error handling remains responsible for the error response.
• Run compiled Rust test binaries with --quiet in the database matrix, removing successful-test chatter while preserving failures and captured diagnostics.
• Preserve an already-positioned nested error instead of wrapping it again, and return nested run_sql errors without adding repeated context.
• Assert that the recursive-inclusion fixture does not expose repeated run_sql: unable to run context.

Before

From the linked job:

running 75 tests
test basic::test_static_files ... ok
test configuration_docs::configuration_md_documents_every_option ... ok
... dozens of other passing tests ...
test sql_test_files::run_all_sql_test_files ... FAILED

---- sql_test_files::run_all_sql_test_files stdout ----
ts=... level=error msg="In \\"tests/sql_test_files/component_rendering/error_too_many_nested_inclusions.sql\\": ... run_sql: unable to run ... run_sql: unable to run ... [repeated recursive context]" target=sqlpage::webserver::database::execute_queries
...
Test timeout: tests/sql_test_files/data/fetch_with_meta_error.sql

After

The same failure retains the actionable test and panic while removing passing-test chatter and the duplicate recursive log:

running 75 tests
sql_test_files::run_all_sql_test_files --- FAILED

---- sql_test_files::run_all_sql_test_files stdout ----
...
Test timeout: tests/sql_test_files/data/fetch_with_meta_error.sql

For a recursive inclusion request in development, the response now contains one positioned error with the Too many nested inclusions message, rather than a repeated run_sql: unable to run chain. Production behavior remains the generic safe error response.

Validation

• cargo test --quiet
• cargo fmt --all -- --check
• cargo clippy --all-targets --all-features -- -D warnings
• git diff --check