fix: recognize dotted property names in index extraction

[pantierra]

Technical Context

• Related Issues: queryable_indexes field regex does not match dotted property names (duplicate indexes) #465
• Breaking Changes: No

Description

queryable_indexes() (and the pgstac_indexes/pgstac_indexes_stats views) extract property names from index definitions using a regex whose character class excludes .. Dotted queryable names (e.g. monty:impact_detail.value) fail to match.

Because the field can't be extracted, pgSTAC doesn't recognize existing indexes on dotted fields, so maintain_partitions() creates a new duplicate index every reload/sync instead of no-oping.

Therefore I suggest we widen the capture group to allow . (and other valid STAC path chars): [a-zA-Z0-9:_.-]+.

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Checklist

• Linting: Does not apply for SQL-only change.
• Tests: Tests pass. I have included new tests for these changes where applicable.
• Edge Cases: I have manually verified "unhappy paths" and edge cases beyond the basic success criteria (e.g., database connection timeouts, malformed input, strict mapping rejections).
• Documentation: Added to CHANGELOG.md. No need for more documentation
• Accountability: I can explain the implementation logic for every line of code submitted.

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AI tool usage

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