Closes#2720 (partial — logs scroll fix).
Make body.logs-shell a full-viewport flex column so the visible .logs-pane
fills the remaining height and .journal-output (already flex:1 overflow:auto)
scrolls its content. Also handle the AUDIT tab's <div> output the same way.
The tab bar and toolbar stay anchored at the top; only the log text scrolls.
Adds an AUDIT sub-tab to /logs.html (alongside BUILD / AGENT / SYSTEM),
consuming GET /api/audit-log ({ entries, total }). A read-only filterable
table: when / agent / action / target / outcome / detail, newest-first,
with a 'latest 500 of N' header from total and a client-side substring
filter. Outcome badges colour ok green / err red, with an err whose detail
starts 'denied:' rendered amber + labelled 'denied' (capability refusal
reads distinct from an execution failure). Lazy-fetched on tab show (like
SYSTEM); a 30s ticker keeps the relative timestamps honest.
The audit_log store + endpoint landed in the prior audit-log backend work;
this is the operator-visible surface for it. Resolves#1647.
The /logs.html header puts a flex:1 sub-tab strip (`.logs-tabbar`) next
to the ← home back-link inside the flex `.page-header`. The strip is
itself a flex container, so its default `min-width: auto` keeps it at its
intrinsic content width and — without an explicit nowrap on the parent —
it gets pushed onto its own row under the back-link.
Mirror the working dashboard chrome (`.dashboard-chrome` / `.tabbar`,
which sets `flex-wrap: nowrap`): make `.page-header` explicitly nowrap and
give `.logs-tabbar` `min-width: 0` so it shrinks to share the row instead
of wrapping. Affects every standalone page that uses `.page-header`
(flow / logs / stats / settings); the nowrap is correct for all of them.
Adds @hive/shared/tabs.js — createTabStrip(tabbar, {defaultId, onShow}):
a hash-routed tab strip that resolves controls by `[data-tab="<id>"]`
inside the passed container and panels by `[data-tab-pane="<id>"]`,
toggling `.hive-tab--active` + aria-selected + the panel's `hidden`, and
firing onShow(id) for per-tab side-effects. Always hash-routed (deep-
linkable + back/forward), no element-resolver callbacks (convention over
config), per the #1464 design review.
Wires it up: @hive/shared exports `./tabs.js` + `./tabs.css`, and
common.css @imports tabs.css (component structure, not a swap target, so
inlining is fine — unlike theme.css).
Migrates the logs sub-tabs as the first consumer: markup uses
`.hive-tab`/`data-tab`/`data-tab-pane`, logs.css drops the duplicated
base styles (keeps only its `flex:1` layout delta), and logs.js swaps its
activeTab/showTab/hashchange for createTabStrip (onShow lazy-loads the
SYSTEM tab). Behaviour-preserving. aria-selected is now standardised.
Adds ?agent=name and ?unit=svc URL params to pre-select the agent on
the AGENT tab (used by the per-agent overflow menu journal logs link).
Last-fetched timestamp chip shows how stale the output is.
Agent selection is NOT persisted to localStorage — URL params only.
