[GH-2678] Add SVG visuals for measurement functions (Phase 4)

[jiayuasu]

What is this PR about?

Phase 4 of GH-2678: Add SVG visual illustrations for all 21 measurement functions.

Changes

• 21 new SVG files in docs/image/ST_<Name>/ST_<Name>.svg
• 63 updated doc files (21 SQL + 21 Flink + 21 Snowflake) with image references

Functions covered

Category	Functions
Distance	ST_Distance, ST_3DDistance, ST_DistanceSphere, ST_DistanceSpheroid, ST_FrechetDistance, ST_HausdorffDistance, ST_MaxDistance
Closest/Longest	ST_ClosestPoint, ST_LongestLine, ST_MinimumClearance, ST_MinimumClearanceLine
Area	ST_Area, ST_AreaSpheroid
Length	ST_Length, ST_Length2D, ST_LengthSpheroid
Perimeter	ST_Perimeter, ST_Perimeter2D
Angle	ST_Angle, ST_Azimuth, ST_Degrees

Visual style

• Distance: Two geometries (blue A, red B) with dashed green measurement line and arrows
• Area: Polygon with green highlighted fill and "- Area: Polygon with green highlighghlighted in green with "Leng- Area: Polygon with green highlighted fill and "- Area: Polygon with green highlighghlighted in green with "Leng- Area: istance line to - Area: Polygon with green highlighted fill and "arthest points
• Angle: Rays with green angle arc annotation
• Fréchet/Hausdorff: Coupling lines between corresponding vertices

Image placement

Images are inserted after the complete Introduction section and before the Format line, consistent with Phases 1-3. Multi-line introductions (with notes, tips, warnings) are handled correctly — image is placed after the full intro block.

Closes #2678 (partial — Phase 4 of multi-phase effort)

[Copilot]

Pull request overview

This PR adds SVG visual illustrations for 21 measurement functions in Apache Sedona's documentation, as Phase 4 of a multi-phase effort (GH-2678). Each function gets a new SVG file and image references in three documentation variants (SQL, Flink, Snowflake).

Changes:

• 21 new SVG files added under docs/image/ST_<Name>/ST_<Name>.svg, covering distance, area, length, perimeter, angle, and closest/longest measurement functions.
• 63 markdown documentation files updated (21 SQL + 21 Flink + 21 Snowflake) to embed the corresponding SVG images after the Introduction section and before the Format line.
• SVGs follow the established visual conventions from prior phases (500×300 viewBox, consistent color scheme for inputs/results/measurements).

Reviewed changes

Copilot reviewed 63 out of 84 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
docs/image/ST_Distance/ST_Distance.svg (and 6 similar distance SVGs)	New SVGs showing two geometries with dashed measurement line
docs/image/ST_Area/ST_Area.svg, ST_AreaSpheroid.svg	New SVGs showing polygon with highlighted area fill
docs/image/ST_Length/ST_Length.svg, ST_Length2D.svg, ST_LengthSpheroid.svg	New SVGs showing polyline with length annotation
docs/image/ST_Perimeter/ST_Perimeter.svg, ST_Perimeter2D.svg	New SVGs showing polygon with highlighted perimeter
docs/image/ST_Angle/ST_Angle.svg, ST_Azimuth.svg, ST_Degrees.svg	New SVGs showing angle/azimuth measurement arcs
docs/image/ST_ClosestPoint/ST_ClosestPoint.svg	New SVG showing closest point between geometries
docs/image/ST_LongestLine/ST_LongestLine.svg, ST_MaxDistance.svg	New SVGs showing max distance/longest line
docs/image/ST_MinimumClearance/ST_MinimumClearance.svg, ST_MinimumClearanceLine.svg	New SVGs showing clearance measurement
docs/image/ST_FrechetDistance/ST_FrechetDistance.svg, ST_HausdorffDistance.svg	New SVGs showing coupling lines between geometries
docs/api/sql/Measurement-Functions/*.md (21 files)	Added image references with ../../../image/ path
docs/api/flink/Measurement-Functions/*.md (21 files)	Added image references with ../../../image/ path
docs/api/snowflake/vector-data/Measurement-Functions/*.md (21 files)	Added image references with ../../../../image/ path

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