Add snapshot selection to manifest inspection

[emecii]

Rationale for this change

Implements the manifest-inspection snapshot-selection part of #1053; the umbrella issue remains open.

table.inspect.manifests(snapshot_id=...) selects a retained snapshot using the existing lookup helper. Calls without an ID retain current-snapshot and typed empty-table behavior; unknown or expired IDs raise the existing lookup error.

Partition summaries use the selected snapshot's schema and each manifest's partition spec. When a retained manifest references a dropped source, resolve its field ID from retained schemas. This keeps old manifests readable after schema and partition evolution, including a reused column name with a different field ID/type. Snapshots without a schema ID follow the existing current-schema fallback convention; unavailable recorded schemas warn before falling back.

all_manifests() retains its signature and all-snapshot reference rows. It receives the historical summary correction through the shared generator. No general readable-metrics or bound-conversion changes.

Are these changes tested?

Real local catalog tests cover old/current selection, exact manifest paths, empty tables, invalid and expired IDs, renamed/dropped partition sources, mixed partition specs, reused names, null/empty bounds, type promotion, schema fallback, and all-manifest references.

• Inspection suite: 21 passed.
• Full local unit target: 4,028 passed, 3 skipped, 1,571 deselected.
• make lint: passed.
• Apache RAT: passed on a clean export of the commit.
• Restoring current-schema-only decoding makes two historical-summary cases fail.

Spark/Docker parity, cloud suites, other Python/platform combinations and documentation build were not run. Historical fallback relies on retained schema metadata; it does not recover types from removed metadata files.

Are there any user-facing changes?

Yes: optional snapshot_id on InspectTable.manifests, documented in the API guide. Existing calls remain valid; historical partition summaries use retained schemas/specs.

AI assistance

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