Changelog

v0.2.1

PhoenixMountable.Path.path/3 and PhoenixMountable.Mount.sibling/2: paths under another mount of the same router, by its name, for a library whose definitions link to each other (an admin to its public page).

use PhoenixMountable.Install declares a library's installer in one use: mounts, the migration, a LiveView hook, style sheets, Tailwind sources and the supervisor, then the library's own install/1. It is an Igniter task (mix igniter.install my_lib) and, in a host without Igniter, says how to get it.
PhoenixMountable.Igniter.mount/4 mounts in any scope, with its pipelines, options ({web} is the host's web module) and a re-exported macro (:import), and imports the library's formatter, so the host writes the mount without parentheses.
PhoenixMountable.Igniter.add_hook/4 and add_css_imports/4 edit the host's app.js and app.css (PhoenixMountable.Igniter.HostAssets), or give the lines to add where they cannot.
TypeScript types for the browser helper.
A pending upgrade under pending_migrations: :raise is checked again on each use, so running the migration takes effect without a restart.
The migration generator compiles without warnings on Elixir 1.19 and 1.20.

The first release.

Definition modules (use PhoenixMountable) and generated mount macros that insert routes, live sessions, controllers and plugs into a host router, with or without LiveView.
Options validated with NimbleOptions when the host compiles, :verify checks after the host router compiles, and normalize_options/1.
PhoenixMountable.Mount in LiveViews, controllers and plugs, with the request's CSP nonces.
Assets: Embedded, Static (with Vite manifests) and Host strategies, layout components, a browser helper, and reloads of pages running a previous build.
~m, paths relative to the mount, verified after compilation.
Processes per mount (lazy or with PhoenixMountable.Supervisor), PhoenixMountable.Singleton, PhoenixMountable.PubSub and telemetry.
PhoenixMountable.Migrations: versioned migrations on PostgreSQL, MySQL and SQLite with a tracking table, install options, legacy adoption, baselines, expand and contract versions, concurrent index builds, lock timeouts, SQLite table rebuilds that keep the host's columns, batched backfills, schema checks and a test kit.
mix phoenix_mountable.gen.migration, mix phoenix_mountable.check, mix phoenix_mountable.backfill, and PhoenixMountable.Igniter.
PhoenixMountable.TestHost and PhoenixMountable.Test.