docs(visuals): rebuild the page around the map's Legend card

[MrAlders0n]

The region map's legend now ends with a "What do these mean?" link to https://wiki.meshmapper.net/visuals/ (dev/index.php:20150, Server dev @ 91c3a2f). That makes docs/visuals.md the documented answer for every mark on the map, and it was stale, and on two points inverted: pink was given as Active when pink is New, and orange as New when orange is TX coverage.

What changed

docs/visuals.md is rewritten in the legend's own order (coverage squares, repeaters, links, signal) so the card and the page can be held side by side. The H1 now matches the nav entry.

• New: chip anatomy, the five repeater states, the observer eye, group badges, the four neighbour link kinds, the Backbone overlay, and the SNR bands.
• Deleted: ## Repeater Icons, which described marks that no longer exist.
• Carried over verbatim: The Grid System, Ping Types Defined, Private Repeaters. Ping Types gains TRACE and the Selected square, which the legend lists and the page did not.
• Colours are named with their Default-palette hex, under one note that the four colour vision palettes remap all of them.

docs/layers.md: a Backbone row, the two missing neighbour link kinds (Reported, Uploaded), and chip wording on the Repeaters row.

docs/duplicaterepeaterid.md: carried the same wrong colours (New | Orange Icon) and is corrected to match.

Where the handoff brief and the source disagreed

Per the brief's own rule, the source won. These are worth a read before merging.

The dash/solid instructions were inverted

lineDash is assigned at :19725, :19985, :19995, :20004 and never read. No polyline in drawLine (:20031-20034) or in the neighbour draws (:15804, :15832, :15854) passes dashArray, and the MapLibre shim only routes to its dashed layer on filter: ['!=', ['get','dash'], ''] (:1385, :1600). So every popup line and every neighbour link renders solid.

• The brief said to fix line 77 ("Solid Coloured Line") to dashed. That line was correct; making the change would have introduced a new error. Left alone.
• The brief said line 79 (red dashed duplicate line) "is still correct". Red yes, dashed no. Fixed.
• Line 78 ("Blue Dashed Line" for Via) was also wrong and the brief did not flag it. Fixed.

⚠️ Server bug this surfaced

The legend card paints Inferred, fresh (:20127) and Route path (:20131) as 2px dashed swatches, but both draw solid on the map. The legend and the renderer disagree. The wiki cannot fix this; this PR documents what the map actually draws. Worth a Server-side issue to decide which side moves.

Other corrections

brief said	source says
"three colour-vision-deficiency palettes"	Four CVD options plus Default in the menu (:4860); deuteranopia is aliased to protanopia (:14712), so three distinct blocks back them.
palettes remap every colour	True, and backbone becomes white, not gold, in all three CVD blocks. The chip body and hairline stay fixed in every mode (:9291).
badge ring is "the state most of them are in"	A plurality, ties broken by fixed order (:9485). Page avoids implying a majority.
zooms "when the badge is large and you are zoomed well out"	Fan when zoom >= 14 OR point_count <= 18 (:9896). Zoom only when both fail, with a fallback to fanning, so a group is never unopenable.
gold "replaces Active and nothing else"	Correct, and stronger than the legend's own tooltip, which mentions only aged and ambiguous. :16641 is if (repState === 'active') repState = 'backbone'; so New keeps pink too.
(not mentioned)	Gold and the share show always, not only with the overlay on (:16636, BB_LABEL_PCT :10050).
shares "are not slices of the headline 54%"	There is no headline number rendered any more (removed :20077). The page says the shares add up to about half and never mentions a headline.
orange links are "4 to 7 days"	3 days is a hard literal (:15405); the 7 is NB_RETENTION.inferred, admin-settable (:485). Written as settable.
SNR mid band is "orange"	signal.medium is #856404, a dark mustard (:14657). There is also a grey #6c757d fallback the brief omitted (:20025).
"11 sites on YOW, 25 on SEA"	Real, but a developer comment naming 2 of 463 regions (:10069). Used as scale, not as region names.
stale_repeater_hours default 24	Confirmed as the code default, but regions vary (PNW/SEA are 96). Written as "24 hours unless they changed it".

Confirmed accurate in the brief: all five link hexes, all five chip hexes, the BB_RAMP values and order, the 50% cut, and the group-as-one-pool rule.

Verification

• mkdocs build --strict clean, with the same deps CI installs. No new warnings against the baseline build of main (the two pre-existing INFO notes about region_boundaries.md and onboarding.md are unchanged).
• All three new cross-links from layers.md resolve to real anchors (#repeaters, #links-between-repeaters, #the-backbone), as do layers.md#accessibility and every in-page anchor.
• Em/en dash counts unchanged in all three files (visuals 2, layers 33, duplicaterepeaterid 2), so no new ones were introduced and no pre-existing ones were swept.
• grep confirms no page still says orange means New or pink means Active.

🤖 Generated with Claude Code

https://claude.ai/code/session_014HA5hZ2YdkCkgrNkxBrSRN