bearer: silence the std logger the benchmarks were timing

sr-ht-core's auth.DecodeBearerToken calls log.Printf on every token it
refuses, so BenchmarkValidate/invalid wrote one line per iteration. The cost
was not the file: log.Printf takes a mutex, and the case reported 925 ns/op
where the work is 92.5.

The file was a hazard too. An unfiltered run of this package produced 9.5
million lines and 901 MB, and benchfmt skips what it cannot parse — so
bench.sr.ht would have accepted that upload and reported success over it.

Ignore cover.out and bench.txt: make cover and make bench write them into
the checkout.

bd init: initialize beads issue tracking

gitignore the in-repo git worktree directories

chrome: shared page chrome for the instance's custom services

Extract the nav/chrome idiom that compare, spec, dolt and cover each
carried as a private copy (and bench was about to fork as a sixth):
BuildNav over the shared config.ini with the canonical ordering and
paste/pages/hub exclusions, a per-request Page with login/logout/profile
URLs against meta's unified login, embedded srht-nav / srht-env-banner
partials (circle brand + red service label + switcher + login box), and
the generic dict/shortsha template helpers.

Policy decisions the copies had drifted on are baked in: switcher only
for authenticated viewers, hub excluded in the builder rather than the
template, profile link prefers hub's ~username page, environment name
uppercased for the banner. Service-specific needs surfaced by the cover
survey get seams instead of copies: ExtraNav for extra switcher entries,
ContainerClass for full-bleed pages, the config section as an explicit
parameter for the active check.