Add RSpec specs for Interaction, OutputGenerator, RequestContext, and UserInfo

[mackuba]

Motivation

• Add unit coverage for core feed/request objects to catch regressions in interaction mapping, output generation, request context handling, and user token parsing.
• Conform tests to the requested project style using top-level describe, it "should ..." names, should matchers, and expect { ... }.to raise_error for exceptions.

Description

• Added spec/blue_factory/interaction_spec.rb to validate Interaction attribute mapping and unknown-event handling.
• Added spec/blue_factory/output_generator_spec.rb to test valid feed output, cursor/reqId rendering, pin/repost reasons, and invalid-response error cases.
• Added spec/blue_factory/request_context_spec.rb and spec/blue_factory/user_info_spec.rb to cover environment access, UserInfo token parsing, JWT payload decoding, and authorization error handling.
• Updated spec/spec_helper.rb to enable :should syntax and adjusted spec/blue_factory_spec.rb to use a top-level describe and should matcher.

Testing

• Attempted to run bundle exec rspec, which failed in this environment with bundler: command not found: rspec, so the test suite could not be executed here.
• All new specs were added under spec/blue_factory/ and committed; they are ready to run in an environment with the project dependencies installed.

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Codex Task