fix: deliver the remaining fork delta of the 1112 sync wave - #874

* fix: close the remaining #562 visual-audit defects

The recheck of the #562 fixes on f7a8158 found six items only
partly fixed, two not fixed and one regression. This closes them, except item
12, which the frozen F06/F04 0.1.0 contracts define as discontinuous by design.

Drawings:
- B draws a straight spine with chamfered right bowls, so it no longer reads
  as 8 ("DET B" read "DET 8") (item 26).
- The decimal point is centred between its digits; "3000.000" read
  "3000 .000" (item 27).
- A dimension label steps at most two text heights to clear the body and
  otherwise stays beside its line: the item 27 stepping walked a height
  label inside a 3000 mm beam to the far end, metres from its line.
- A detail's parent-side circle carries the detail's title, and callouts of
  details on one region stack instead of overwriting each other (item 8).

Engine:
- A member mirror completes the roll re-encode with the section's symmetry:
  an equal-leg angle takes a quarter turn and a section symmetric left to
  right a half turn, with the section position rotated back, so both are the
  exact world mirror. An unequal angle, a Z or an asymmetric custom outline
  refuses with UNSUPPORTED_GEOMETRY instead of rendering the true image
  composed with a flip (item 4).

Window:
- A selected bolt group is named in the status line and shown with a neutral
  note instead of a red load failure (item 15).
- The snap strip scrolls in the room the entity strip leaves instead of being
  painted over it at 800 px (item 47).
- The library's selected-model panel measures its details and lets the image
  shrink or go, so State and Open model fit at 1100x680 on both tabs (item 25).
- The mass row shows the engine's kg_display (22.54), as every report does.
- Grid bubbles keep clear of the pane frame stroke (item 38).

Refs #562

Claude-Session: https://claude.ai/code/session_01HF6nmWCNmnwESuVYDnreeF

* fix: address the review of the remaining #562 fixes

Review findings on the previous commit, each checked against the code:

- A mirror of an element that shares an instance definition refuses with
  DEPENDENCY_CONFLICT, as a split does. The update rebuilt the other
  instances' patch without the mirror, so they took the mirrored body under
  their unmirrored authored state; the mirror branch added to shared_with
  could never run and is removed.
- A dimension label blocked on its own side within the step cap tries the
  other side of its line before falling back beside the line, so a deep body
  no longer puts the label back on its strokes.
- Custom outlines compare as cyclic sequences (the image read backwards must
  equal a contour from some start), not as vertex sets, so two polygons on one
  symmetric vertex set are no longer classified as symmetric.
- Detail callouts get twice the names placed plus one tries: one placed name
  can block two consecutive lines.
- The world-mirror test covers every section anchor (Right/Front, Centre/Back)
  for the equal angle and the hat; the CLI test asserts the stored roll and
  the shared-instance refusal.
- The library keys the measured details height on the tab and the model; the
  quantities rows carry their formatter instead of matching the label; the
  bolt-group lookup compares typed ids.

Refs #562

Claude-Session: https://claude.ai/code/session_01HF6nmWCNmnwESuVYDnreeF

* fix: keep the mirror contract of the 1111 review and document the shared-instance refusal

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Co-authored-by: Claude <[email protected]>
Co-authored-by: axisrow <[email protected]>