Fixes a regression + a longer-standing inconsistency (mara: "agent
page link icons is different from swarm ui, settings icon looks weird
since component extract").
- The `SettingsMenu` shared-component extraction swapped swarm-ui's
original inline-SVG gear trigger for a plain `⚙` text glyph (matching
agent's `MetaNav`, which was itself still on the `🔗` emoji at the
time). An emoji/text glyph is rendered by the OS/browser's own font
at that font's fixed metrics — it can never match a neighbouring
icon in size or weight, and some codepoints (the gear included)
aren't even reliably covered by every font.
- New `@hive/shared/icons.js` (`GearIcon`, `LinkIcon`) — the exact SVG
markup that used to live only in swarm-ui's `SettingsMenu`/
`LinksMenu` as two separate inline copies, now the one shared source.
- `SettingsMenu` (shared) uses `GearIcon`; agent's `MetaNav` and
swarm-ui's `LinksMenu` both use `LinkIcon` — three consumers, one
rendering path, matching stroke/viewBox/size everywhere.
Verified with real screenshots on both agent and swarm-ui — both
trigger icons render as the same crisp line-icon style now.
4175ae86e3