fix(map): thinner always-on marker outline — was dominating at zoomed-out levels

[Kpa-clawbot]

Operator feedback on #1334

PR #1334 (the #1293 marker a11y change) added a baked-in white outline at stroke-width=2 to every node marker via makeRoleMarkerSVG. Operator reports it's too heavy and dominates the map at zoomed-out levels — every node reads as a "big white blob with a colour core", which actually drowns out the per-role shape silhouette at the exact zoom levels where the shape distinction matters most.

Fix

Drop the always-on stroke from 2 → 1 across all marker producers:

Producer	Before	After
public/roles.js makeRoleMarkerSVG (circle / square / triangle / diamond / hexagon)	stroke-width="2"	stroke-width="1"
public/roles.js makeRoleMarkerSVG (star branch)	stroke-width="1.5"	stroke-width="1"
public/live.js addNodeMarker inline fallback SVG	stroke-width="2"	stroke-width="1"
public/map.js makeMarkerIcon switch (all shapes)	stroke-width="2" / "1.5"	stroke-width="1"
_highlightRing (pulse on selected/active)	weight: 3 → 2	unchanged

The highlight ring used by pulseNodeMarker is the one place where a heavy outline carries real signal (selected state), so it stays at weight 3 → 2. The always-on shape stroke is now just enough to keep silhouettes distinct on both Carto dark and light basemaps without dominating the surrounding terrain.

Constraints preserved

• Shape variation (a11y(map+legend): use shape variation per role/type (not color only) + avoid blue-on-blue dot stacking + colorblind-safe palette #1293) — per-role shapes still rendered, helper untouched except for stroke width.
• Colorblind palette — fills/colors unchanged, all via CSS variables / ROLE_COLORS.
• Highlight ring still visible — pulse weight ≥ 2 retained and asserted.

Tests

New: test-marker-outline-weight.js (added to test-all.sh unit suite)

• Asserts every stroke-width literal in makeRoleMarkerSVG is <= 1.
• Asserts live.js inline fallback SVG stroke-width <= 1.
• Asserts the _highlightRing (ringHl.setStyle({ weight: N })) keeps at least one weight >= 2 so highlight stays visible.

Red commit (d17cfcc) fails on assertion; green commit (6cfe99b) flips it.

Existing test-issue-1293-marker-shapes.js still passes — the shape-variation and outline-ring highlight contracts are intact.