fix(env): allowlist JVSPATIAL_POSTGRES_* keys

[eldonm]

Summary

• The Postgres backend in jvspatial/db/factory.py and jvspatial/db/postgres.py reads JVSPATIAL_POSTGRES_DSN, JVSPATIAL_POSTGRES_MIN_POOL_SIZE, JVSPATIAL_POSTGRES_MAX_POOL_SIZE, and JVSPATIAL_POSTGRES_POOLER_MODE, but the canonical ALLOWED_ENV_KEYS set in jvspatial/env_adapter.py did not list them.
• Result: any PG deployment logged Unknown JVSPATIAL_* env var 'JVSPATIAL_POSTGRES_DSN' ignored. at boot even though the value was honored. With JVSPATIAL_STRICT_ENV_ALLOWLIST=true the warning escalates to a fatal ValueError and breaks startup.
• Adds the four keys to the # Database block in ALLOWED_ENV_KEYS, alongside the existing Mongo / DynamoDB entries.

Test plan

• pytest tests/api/test_env_allowlist_audit.py -q → 5 passed
• Confirmed all four keys are referenced in jvspatial/db/factory.py and jvspatial/db/postgres.py via grep -rn 'JVSPATIAL_POSTGRES_' jvspatial/
• CI green

🤖 Generated with Claude Code

[github-actions]

Benchmark comparison

Threshold: ±25% (informational, does not block merge)

benchmark	baseline (s)	current (s)	delta	status
tests/benchmarks/test_deferred_save_benchmarks.py::test_bench_deferred_save_batched_100	0.050066	0.040027	-20.1%	OK
tests/benchmarks/test_deferred_save_benchmarks.py::test_bench_immediate_save_100	0.052645	0.040955	-22.2%	OK
tests/benchmarks/test_jsondb_benchmarks.py::test_bench_jsondb_batched_saves_500	0.541573	0.419886	-22.5%	OK
tests/benchmarks/test_jsondb_benchmarks.py::test_bench_jsondb_count_empty_query	1.159199	0.883640	-23.8%	OK
tests/benchmarks/test_jsondb_benchmarks.py::test_bench_jsondb_count_filtered	1.361629	1.163736	-14.5%	OK
tests/benchmarks/test_jsondb_benchmarks.py::test_bench_jsondb_find_filtered	1.017479	0.857027	-15.8%	OK
tests/benchmarks/test_jsondb_benchmarks.py::test_bench_jsondb_save_throughput	0.001761	0.001464	-16.9%	OK
tests/benchmarks/test_sqlite_benchmarks.py::test_bench_sqlite_count_empty	0.327689	0.224943	-31.4%	IMPROVED (-31.4%)
tests/benchmarks/test_sqlite_benchmarks.py::test_bench_sqlite_count_fallback_via_regex	0.389060	0.299404	-23.0%	OK
tests/benchmarks/test_sqlite_benchmarks.py::test_bench_sqlite_count_pushdown	0.327183	0.273227	-16.5%	OK
tests/benchmarks/test_sqlite_benchmarks.py::test_bench_sqlite_find_fallback_via_regex	0.347182	0.272155	-21.6%	OK
tests/benchmarks/test_sqlite_benchmarks.py::test_bench_sqlite_find_pushdown	0.340361	0.219355	-35.6%	IMPROVED (-35.6%)
tests/benchmarks/test_sqlite_benchmarks.py::test_bench_sqlite_sort_limit_pushdown	0.355369	0.257158	-27.6%	IMPROVED (-27.6%)

[eldonm]

Closing — folding into existing WIP on dev rather than landing as standalone PR.