Every sub-page tabbar (logs.html, credentials.html, core.html,
builds.html) hand-wrote the same <nav class="hive-tabbar"><a
class="hive-tab">...</a></nav> boilerplate and then called
createTabStrip() on it after the fact. Add <hive-tab-strip>, a
markup-owning custom element (same reuse-boundary pattern as
<hive-menu>/<hive-side-panel>) that renders that markup from a
declarative tabs list, then wires the existing createTabStrip()
behaviour over what it just rendered — no behaviour duplication.
Convert all four sites to use it: each page's JS now calls
`.configure({ tabs, defaultId, onShow })` on the tabbar element instead
of `createTabStrip(el, opts)`, and configure() returns the identical
{ show, active } shape so nothing downstream changes. builds.js's
rebuild-queue count pill (builds-tab-count-rebuild) is expressed as a
tab's `badgeId` and renders nested in the same spot.
The dashboard's own tabbar and the two no-pane stats time-range
pickers are a different markup/behaviour shape and are intentionally
left alone.
Pure structural move, no API or behaviour change: tabs.js/tabs.css
move into shared/src/tabs/, matching the one-dir-per-component
layout the other shared components already use (hive-btn,
hive-dialog, hive-toast, hive-menu, side-panel).
Both files are consumed exclusively through @hive/shared's
package.json exports map (./tabs.js, ./tabs.css), never by a raw
relative path, so updating the two export targets is the only
change needed -- none of the 9 call sites (dashboard tabbar, logs,
core, builds, credentials, stats x2, agent stats) touch anything.
Verified the built dashboard/agent bundles still resolve both
files correctly.
