feat(geo): add nearestApproachDistance, expandSpace, && for TGEOMPOINT

[estebanzimanyi]

👀 Reviewers: tier ranking, dependency chains and the standards checklist live in doc/contributing/reviewer-guide.md.

Summary

Adds three MEOS-backed functions that complete BerlinMOD portable SQL coverage on MobilityDuck:

• nearestApproachDistance(TGEOMPOINT, TGEOMPOINT) → DOUBLE — wraps nad_tgeo_tgeo; returns NULL (not 0) when trips have no overlapping time extent (sentinel DBL_MAX → SQL NULL via ExecuteWithNulls)
• expandSpace(TGEOMPOINT, DOUBLE) → STBOX — wraps tspatial_to_stbox + stbox_expand_space; enables the trip && expandSpace(other, dist) index pre-filter in Q10
• &&(TGEOMPOINT, TGEOMPOINT) → BOOLEAN — wraps overlaps_tspatial_tspatial; STBox overlap pre-filter for cross-trip joins

BerlinMOD impact:

Query	Function	Before	After
Q05	nearestApproachDistance	❌	✓
Q10	expandSpace	❌	✓

16/18 queries already worked on the released community extension; this adds the missing 2.

Stacked on: #113 (edge-to-cloud quickstart + SRID/geodetic fix). Merge #113 first; GitHub will rebase this PR onto main automatically.

Cross-references:

• MobilitySpark BerlinMOD portable SQL: estebanzimanyi/MobilitySpark#5
• RFC Temporal Data Lake: MobilityDB/MobilityDB#912

Test plan

• CI green (Linux amd64 + arm64)
• nearestApproachDistance(trip1, trip2) returns correct float, NULL when disjoint in time
• expandSpace(trip, 3.0) returns STBox expanded by 3 units spatially
• BerlinMOD Q05 and Q10 pass with toy dataset via ./berlinmod/run_mduck.sh from MobilitySpark

[estebanzimanyi]

Consolidation note — overlaps with #99 consolidate/tgeompoint-ops-parity

This PR adds three TGEOMPOINT operators (nearestApproachDistance, expandSpace, &&) and touches three files: src/geo/tgeompoint.cpp, src/geo/tgeompoint_functions.cpp, src/include/geo/tgeompoint_functions.hpp.

#99 consolidate/tgeompoint-ops-parity — distance / affine / transforms / geoMeasure covers exactly this surface (the same three files plus more). nearestApproachDistance is the named form of NAD, which is in #99's scope per the squashed commit message.

Suggested resolution

Per docs/PR-COORDINATION.md on #115 (minimise PR count, one PR = one feature):

1. Cherry-pick this PR's commit onto feat(bindings): tgeompoint operations parity — distance / affine / transforms / geoMeasure #99's branch, resolving the inevitable conflict in tgeompoint.cpp (likely just additional registrations side-by-side). Then close this PR.
2. Or: close this PR; the nearestApproachDistance / expandSpace / && registrations get folded into feat(bindings): tgeompoint operations parity — distance / affine / transforms / geoMeasure #99 directly.

I attempted (1) and hit conflicts in tgeompoint.cpp and tgeompoint_functions.hpp. Resolving them needs maintainer judgment on which side of each registration to keep, so I'm pinging here rather than guessing.

Currently mergeable: MERGEABLE for this PR but it would conflict with #99 once both target main.

[estebanzimanyi]

Inspected the diffs more carefully:

This PR adds 3 things:

1. && operator for tgeompoint × tgeompoint — Temporal_overlaps_tgeompoint_tgeompoint impl.
2. nearestApproachDistance(tgeompoint, tgeompoint) named function — Nad_tgeo_tgeo impl.
3. expandSpace(tgeompoint, double) returning STBOX — ExpandSpace_tgeo_double impl.

#99 consolidate/tgeompoint-ops-parity (per its squashed commit message) covers "tdistance / NAI / NAD / shortestLine — distance and nearest-approach family" — so item 2 is duplicated. Items 1 (&& overlap operator) and 3 (expandSpace) may be unique to this PR.

Maintainer choice:

• Confirm feat(bindings): tgeompoint operations parity — distance / affine / transforms / geoMeasure #99 covers items 1 and 3 too → close this PR as duplicate.
• Confirm only item 2 is in feat(bindings): tgeompoint operations parity — distance / affine / transforms / geoMeasure #99 → cherry-pick items 1+3 from this PR onto feat(bindings): tgeompoint operations parity — distance / affine / transforms / geoMeasure #99's branch (the Temporal_overlaps and ExpandSpace impls), close this PR.

I won't blind-resolve since the cherry-pick conflicts in tgeompoint.cpp could lose registrations either way.

[estebanzimanyi]

Superseded by the consolidated parity batch at #126 (feat/parity-additions-batch, commit c53a482) and the final 14-name closing batch at #130 (feat/parity-final-batch, commit 22c64c0).

The work on this branch — nearestApproachDistance / expandSpace / && for TGEOMPOINT — is now part of the squashed addressable-parity surface that brings MobilityDuck to 943/943 = 100.0% of the active addressable temporal + geo names. Closing to keep the review queue focused on the three active stacked PRs (#126 → #130 → #129) and the four orthogonal PRs (#105 / #111 / #113 / #117 / #120).

Branch feat/berlinmod-geo-functions2 is left intact; reopen if a regression appears in the squashed batches and the originals turn out to carry a unique fix.