Move Rails-compatible methods to lib/rails; date deprecations

[trans]

First step of separating the methods Facets borrowed from ActiveSupport from the ones Facets endorses as its own. The per-file decisions came from a triage of all 40 Facets files that overlap with ActiveSupport 8.1.

1. New lib/rails tree (f9f1fa6)

These files move to lib/rails/facets/, with their tests and demos under test/rails and demo/rails:

• hash/symbolize_keys, hash/stringify_keys, hash/to_options, hash/slice
• array/extract_options
• module/mattr, module/cattr, class/cattr, cattr
• file/atomic_write
• date (previously in lib/standard)

lib/rails is added to the gem's require_paths, so require 'facets/hash/slice' and friends still work.

Also in this commit:

• lib/rails is added to .index, Indexfile, etc/test.rb and the Rakefile, which gains test:rails and qed:rails tasks.
• MANIFEST has the moved paths relocated. It was already out of date before this PR and mast wasn't available to regenerate it, so only the moved entries were edited.
• Fix: hash/to_options only loaded symbolize_keys and never defined Hash#to_options. It now aliases to_options and to_options! as Rails does, and has a new test.

2. Deprecations get a removal date (aa011ae)

Each of these now names 2027-09-30 in its @deprecated note and in its warning:

• Kernel#returning
• Module#alias_method_chain
• Array#uniq_by!
• Enumerable#uniq_by
• Kernel#silence_stream
• Facets' fallback Time#to_time, which is only defined when date isn't loaded

The first four already warned; they only gain the date.

silence_stream: Rails removed it in 5.0 because reopening STDOUT/STDERR affects every thread in the process. Its logic now lives in Kernel#silence, and silently, silence_stderr and silence_stdout call silence, so they keep working without a warning. silence_stream warns and then delegates to silence. The docs for silence now say it affects the whole process.

3. Warning for Rails methods loaded by require 'facets' (65d5b5f)

require 'facets' (and facets/essentials) still provides Hash#slice!, #symbolize_keys, #stringify_keys, #to_options and Array#extract_options!, but will stop after 2027-09-30. Instead of loading those files outright, the loaders now call Facets.rails_bridge, which defines a small stub for each method. The first call to a stub:

1. warns, naming the file to require,
2. loads that file, which replaces the stub,
3. retries the call.

warning: Hash#slice! will no longer be loaded by `require 'facets'` after 2027-09-30. Add `require 'facets/hash/slice'` to keep using it.

• Each method warns at most once per process.
• Requiring the file directly avoids the stub and the warning entirely.
• If a method is already defined when require 'facets' runs, for example by ActiveSupport, it is left alone and not stubbed.
• The set of methods require 'facets' defines is unchanged, apart from the new Facets.rails_bridge and the to_options fix.

Testing

• rake test: 1,252 tests, all passing: the previous 1,248, 2 new to_options tests and 2 new rails_bridge tests.
• rake qed: 153 demos with 8 failures and 2 errors. Those same failures were already there before these changes, so nothing new.
• Ran by hand:
  • silence, silently, silence_stderr and silence_stream: the output is hidden inside the block and comes back afterwards, and only silence_stream warns.
  • The bridge stubs: each warns once, then works normally, and there's no warning when the file is required directly.
• I didn't run the experimental JRuby job locally. It already fails on main because URI.hash_to_query comes out private on JRuby 10.1 (see the comment on Simplify block default passing in cattr and mattr #325).

🤖 Generated with Claude Code

https://claude.ai/code/session_01E2Njj4j1r9twkVcXsMySLW

[trans]

CI status: all required jobs pass (Ruby 3.1–3.4, head, TruffleRuby). The only red check is the experimental Ruby jruby on ubuntu job, and it isn't caused by this PR.

• It's the same error main already has: private method 'hash_to_query' called for module URI at lib/standard/facets/uri.rb:28 (see the comment on Simplify block default passing in cattr and mattr #325). This PR doesn't touch uri.rb.
• On JRuby, 1,245 of this PR's 1,250 tests pass: 4 are pending and this is the only error. So the moved lib/rails files and their tests work on JRuby too.
• No fix exists yet; it needs its own change to uri/query.rb.

---

Generated by Claude Code