feat(query_client): add pagination support for records queries

[wingding12]

Closes #1608

Summary

Adds built-in pagination support to the Logfire query client to enable downloading more than the 10,000 row API limit.

Changes

• Add iter_paginated_records() method to both LogfireQueryClient and AsyncLogfireQueryClient
• Uses cursor-based pagination with (start_timestamp, trace_id, span_id) by default
• Supports use_created_at=True for paginating over recent data where new rows may be inserted (uses created_at, trace_id, span_id, kind)
• Add PaginationCursor TypedDict and MAX_QUERY_LIMIT constant
• Add documentation in the query API guide
• Add tests with VCR cassettes for both sync and async clients

Usage

with LogfireQueryClient(read_token=token) as client:
    for rows, next_cursor in client.iter_paginated_records(
        select='*',
        where="level >= 'error'",
        page_size=1000,
    ):
        process(rows)
        if next_cursor is None:
            break

[codecov]

Codecov Report

❌ Patch coverage is 91.30435% with 6 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
logfire/experimental/query_client.py	91.30%	2 Missing and 4 partials ⚠️

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