D5: stamp H-ANNULUS-TANGENT as a named miss

[grootstebozewolf]

Stacked on cursor/d3-hshell-hole-cross-e649 @ 3cc5f1a (draft PR #12). Does not reopen #8, #10, #11, or #12. Does not rewrite D2, D3, or D4 lasers.

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.

Remaining R2 (named misses only):

• H-SHELL-N-MIXED — collinear overlap, not a discrete node set
• H-SHELL-HOLE-CROSS — hole ∩ other shares the clip edge; a punch would guess a bite
• H-SHELL-HOLE-X — two holes that cross — a noder, stop
• H-ANNULUS-TANGENT — not strictly inside; 1 node / d+r = R

No other overlay R2 in this PR is an unnamed fallthrough that pretends to be exact.

Split

H-ANNULUS-TANGENT is a named green null, not a laser. CircularDiscOverlay.nestedAnnulus already requires a strict nest (d + r <= R - eps). CIRCLE_5 vs the kit's internal-tangent disc (CIRCLE_INT_TAN: r=3 at (2,0), touches at (5,0)) is 1 node / d+r = R. The kit returns null. This PR gives that miss a name. Do not densify with isApproximate()=false.

The three already-named nulls stay, with their reasons, unchanged.

Already-lasered cells are unchanged: D4 annulus, D2 ODD, different-outer punch, R1.5 crossing, even-n H-SHELL-N.

Out of scope

• No new public API
• No noder
• No densify-as-laser
• No snap-round

Verify

mvn -pl modules/curve -am test -DfailIfNoTests=false -Dcheckstyle.skip=true -Dpmd.skip=true \
  -Dtest=CompoundCurveShellOverlayTest,CircularArcOverlayTest,CircularDiscOverlayTest,CircularDiscPolygonOverlayTest,OverlayNGCurvePhase0Test,OverlayNGCurveRatchetTest,OverlayNGCurvePerfGateTest
mvn -pl modules/curve checkstyle:check
mvn -pl modules/curve pmd:check

All green after this revision:

• CompoundCurveShellOverlayTest 24 / 0 (same-outer hole, different-outer punch, D2 ODD, H-SHELL-HOLE-CROSS, H-SHELL-HOLE-X, H-SHELL-N-MIXED)
• CircularArcOverlayTest 11 / 0 (same three named nulls stay)
• CircularDiscOverlayTest 10 / 0 (D4 annulus + R1.5 crossing + H-ANNULUS-TANGENT)
• CircularDiscPolygonOverlayTest 7 / 0
• OverlayNGCurvePhase0Test 19 / 0
• OverlayNGCurveRatchetTest 43 / 0
• OverlayNGCurvePerfGateTest 78 / 0 (15% slack)
• Checkstyle 0 violations; PMD check on jts-curve succeeded