docs: epic retip only — EPIC_SFA_CURVE_AWARENESS.md Draft v5

[grootstebozewolf]

Documentation honesty retip of EPIC_SFA_CURVE_AWARENESS.md from Draft v4 (2026-08-15, tip 488c48ba) to Draft v5 (2026-08-16).

No Java, tests, or other files. Slack stays 15%. No circular noder. No new public API. Do not merge into #7. Stay a draft against feature/sfa-curve-rgr.

D-HF — not this PR

D-HF honesty lives on draft #45 (cursor/docs-dhf-honesty-ab6e @ 9156544ccdd56ddb341dee670be07eef115d22ca). This PR is not a D-HF source. Do not present both.

#14’s D-HF sentences are print-locked to match #45.

May print

DiscreteHausdorffDistance on #7 has closed-form for two pairs only: single-arc CircularString → single-segment LineString (apex √949/6 − 7/6 ≈ 3.967641), and two circular discs. A single-member MultiSurface of one disc is the same pair, not a third.

Public DHD still sees chords in general. Exact path skips densify; densify 0.05 is not the laser. Keep the spec fail().

May not print

• replace / port / ship DirectedHausdorffDistance
• public DHD is generally closed-form
• densify 0.05 is the laser
• Fréchet / isFullyWithinDistance / Linearizable-on-construct as shipped
• reverse orientedDistance(segment, arc) as laser

Phase 3 no longer says “DiscreteFrechetDistance parameterise by arc length”.

Why

A locationtech maintainer reading Draft v4 would still think #8 is the live stacked branch, OverlayNGCurve stopped at R1.6, LEC was a blank open, and the live meter was “49 methods remaining”. That is stale against #7 @ 210f1b16.

Binding live stack (16 Aug 2026)

• Parent epic: EPIC: SQL/MM Spatial (ISO/IEC 13249-3) Curve Awareness in JTS locationtech/jts#1195. Fork work: this repo’s SFA/SQL-MM curve awareness: Curve rename, arc-aware operations, OverlayNGCurve ratchet (#1195 RGR series) #7, feature/sfa-curve-rgr, tip 210f1b16 (merge of D2: laser H-SHELL-N-ODD as a tangent degenerate NSpan #11).
• PERF-GATE: take the curve path only when it is no slower than densify-then-core #8 PERF-GATE, D4: laser nested-disc SUB/XOR as the exact annulus #10 nested annulus (92fdbb71), D2: laser H-SHELL-N-ODD as a tangent degenerate NSpan #11 odd-n tangent NSpan (d8c5824f) are merged into SFA/SQL-MM curve awareness: Curve rename, arc-aware operations, OverlayNGCurve ratchet (#1195 RGR series) #7.
• Draft D3: keep H-SHELL-HOLE-CROSS; stamp H-SHELL-HOLE-X #12 (3cc5f1a5) stamps H-SHELL-HOLE-CROSS + H-SHELL-HOLE-X. Draft D5: stamp H-ANNULUS-TANGENT as a named miss #13 (73703036) stamps H-ANNULUS-TANGENT. Both stacked, not merged.

What the Goal now says (OV-P1)

Every circular pair that has a closed form has a kit. Everything else is a named miss and the chordsaw. We will not write a circular noder in this PR.

OV-P1 flipped. Remaining named R2: H-SHELL-N-MIXED, H-SHELL-HOLE-CROSS, H-SHELL-HOLE-X, H-ANNULUS-TANGENT. Circular noder + arrangement is OV-P2 / Bar 2 — different epic.

Stale claims removed

• “Intended merge: PERF-GATE: take the curve path only when it is no slower than densify-then-core #8 first, then SFA/SQL-MM curve awareness: Curve rename, arc-aware operations, OverlayNGCurve ratchet (#1195 RGR series) #7”
• Tip 488c48ba / “on PERF-GATE: take the curve path only when it is no slower than densify-then-core #8” as the live branch
• OverlayNGCurve Phase 0 only R0/R1/R1.5/R1.6; CompoundCurve overlay still open
• LEC still open as a blank
• Live meter = “49 methods remaining”
• WKB 8–12 only on PERF-GATE: take the curve path only when it is no slower than densify-then-core #8

R1.7 kits, R-LL, R-AA, D4 nested annulus (16π, covers EEEE / coveredBy EE0E), and typed LEC obstacle distance are described as landed subsets. Full TAGs stay partial, not green. Spec methods stay.

Live meter: #7 green tests + https://www.notion.so/JTS-curve-laser-progress-3bd1c9833b068135bd74e817b67e77eb

Base this PR on feature/sfa-curve-rgr, not locationtech master.