Add the clone engine, CLI, tests, CI, and docs

kage renders every page in headless Chrome, snapshots the final
DOM, strips all JavaScript, and localises CSS, images, and fonts
so a site can be browsed offline as a plain folder of files.

The engine is split into small packages:

  urlx      deterministic URL to local-path mapping and scope rules
  sanitize  remove scripts, on* handlers, and javascript: URLs
  asset     rewrite HTML and CSS references, download assets
  browser   headless Chrome pool over the DevTools protocol
  robots    robots.txt matcher
  clone     the orchestrator: a polite resumable breadth-first crawl

The cli package wires a cobra and fang command surface with two
commands, clone and serve. Every pure package has table tests; the
browser and clone packages add Chrome-driven end-to-end tests that
skip when no browser is present or under -short.

CI runs gofmt, vet, build, race tests, golangci-lint, govulncheck,
and a tidy check on Linux and macOS. A goreleaser config fans one
tag out to archives, deb/rpm/apk, a Chromium-bundled GHCR image,
and the package managers. A tago docs site builds to Pages and
Cloudflare.

cli/styles.go

@@ -0,0 +1,14 @@
+package cli
+
+import "charm.land/lipgloss/v2"
+
+// Styles for the human-readable progress and summary lines. They degrade to
+// plain text when the terminal has no colour profile.
+var (
+	styleTitle  = lipgloss.NewStyle().Bold(true)
+	styleAccent = lipgloss.NewStyle().Foreground(lipgloss.Color("12"))
+	styleOK     = lipgloss.NewStyle().Foreground(lipgloss.Color("10"))
+	styleWarn   = lipgloss.NewStyle().Foreground(lipgloss.Color("11"))
+	styleErr    = lipgloss.NewStyle().Foreground(lipgloss.Color("9"))
+	styleDim    = lipgloss.NewStyle().Foreground(lipgloss.Color("8"))
+)