feat(bindings): tgeography parity — full surface, mirrors tgeometry

[estebanzimanyi]

Summary

Adds the geographic-coordinate-system temporal type tgeography, mirroring the comprehensive tgeometry PR (#90) almost line-for-line. The MEOS C functions backing this surface are subtype-agnostic, so this is largely a mechanical search-and-replace — `TGeometryTypes` → `TGeographyTypes`, `TGEOMETRY()` → `TGEOGRAPHY()`, `tgeometry_` → `tgeography_`, plus a few case-by-case fixes for coercions.

What's included

Layer	Source	What it adds
Type registration + constructors + I/O	src/geo/tgeography.cpp + tgeography_in_out.cpp	The tgeography type, tgeographyInst / tgeographySeq constructors, asText / asEWKT
Foundational accessors / restrict / modifiers / comparison	src/geo/tgeography.cpp	Same surface as tgeometry's foundational layer (~50 names)
Cross-type predicates (box / position / spatial-rels / temporal-spatial-rels / distance)	src/geo/tgeography_ops.cpp	Same surface as tgeometry's cross-type layer (~100 names)
Spatial functions	src/geo/tgeography_ops.cpp	SRID, setSRID, transform, stbox, tgeometry(tgeography) / tgeography(tgeometry) coercions, centroid, convexHull, traversedArea
Aggregate wiring	src/temporal/span_aggregates.cpp, src/temporal/temporal_aggregates.cpp	extent(tgeography) → stbox; TcountAgg(tgeography) → tint; MergeAgg(tgeography); AppendInstantAgg(tgeography); AppendSequenceAgg(tgeography)
Tile / box emitters + analytics	src/geo/tgeography_ops.cpp	spaceBoxes, spaceTimeBoxes, the four *Simplify registrations

Stacked on top of #90

This PR is targeted to merge into cumulative-tgeometry (PR #90). It depends on the tgeometry surface and the prerequisite work (#85 / #86 / #87 / #88) bundled there.

Defaults / quirks

• tgeography defaults to SRID 4326 (WGS84) — geometry payloads in test outputs all start with 0101000020E6100000….
• extent(tgeography) emits SRID=4326;GEODSTBOX rather than STBOX to mark the geographic coordinate system.
• The tgeogpoint coercions are not registered — tgeogpoint is not yet a registered DuckDB type in MobilityDuck. The tgeometry ↔ tgeography coercion is registered.

Out of scope

• tgeogpoint — separate type registration; deferred (npoint/cbuffer/pose/rgeo family scoping rule).
• GiST / SP-GiST index machinery — separate phase.
• I/O round-trip (asEWKB / asHexEWKB / asMFJSON / parsers) — depends on PR feat(bindings): tgeompoint round-trip I/O — Binary/EWKB/HexWKB/HexEWKB/MFJSON #83 landing first.
• spaceSplit / spaceTimeSplit TableFunctions — depends on PR feat(bindings): geo/058 tpoint tile — tiles/boxes/getters + spaceSplit/spaceTimeSplit TableFunctions #79 landing first.

Test plan

• test/sql/parity/041_tgeography_parity.test — 19 assertions covering accessors, time-domain restrict, modifiers, comparison, box predicates, position predicates, spatial functions (including SRID + coercions), and aggregate wiring.
• All 143 cumulative-base assertions still pass (001_set, 025_temporal_tile_getters, 026_single_tile_getters, 030_aggregates_extent, 031_aggregates_skiplist, 040_tgeometry_parity).

🤖 Generated with Claude Code

[estebanzimanyi]

Consolidated into #92 (cumulative parity tip). The full tgeometry → tgeography → tgeogpoint chain is now reviewable as a single PR; this branch's commits are preserved in #92's history.