feat(web): Mardi Gras beads view

Render a beads (bd) issue database as a Mardi Gras parade board: four
lanes — Rolling (in progress), Lined Up (open & ready), Stalled (open &
blocked), Past Stand (done) — plus a marquee of per-lane counts. Cards
show id/title/type/priority/assignee/labels and blocked-by/blocks counts;
an issue-detail pane (?issue=<id>) shows the full issue with its
dependency edges in both directions and its comments thread.

Fingerprints on the issues + dependencies tables and reads everything
through the browse layer (column-name-keyed, so column order is
irrelevant), capped at 2000 rows/table. Status is bucketed via
custom_statuses with name heuristics as a fallback; "blocked" means
is_blocked or an open blocking dependency. Plugs into the view registry
via init()+RegisterView with no framework edits. Purple/gold/green
palette scoped in the template (no scss rebuild needed).

feat(web): pluggable alternative-view registry for repositories

A repository can now expose specialized, read-only "views" chosen by the
shape of its tables, while the generic table browser stays available as a
fallback. A View fingerprints the tables (Applies), builds a model from
the browse layer (Build), and renders its own template; views register at
init time via RegisterView and are dispatched by slug at
/~user/db/view/{slug}. The overview shows a tab per applicable view.

The template loader parses each registered view's template with the
shared chrome, so a new view plugs in by adding two files (its .go with
init()+RegisterView and its .html) plus nothing else — no edits to the
registry, router, loader, or handlers. Build receives the request query
values so a view can offer sub-modes (e.g. a detail pane). No SQL engine
is involved; views read through the existing BrowseSession surface.

rename module to sourcecraft.dev/bigbes/sr-ht-dolt; depend on sourcecraft sr-ht-core

web: router, handlers, and sourcehut chrome

Chi route table per plan, SourceHut chrome port (nav/layout from
core.sr.ht Bootstrap structure), dual-flow clone box, dolt-key
association page with hash-fragment prefill, same-origin CSRF checks.
Handlers depend on small injected interfaces (StoreManager, RepoStore,
BrowseOpener, UserResolver) with production adapters included.