🤖 → feat: extend global config directive to accept name/pattern specifiers

[juniper-shopify]

🤖 → Extend the global config directive to accept optional name/pattern specifiers, mirroring the existing support in cog-type blocks (agent, chat, cmd, etc.).

Motivation

Currently, global { ... } applies configuration to every cog unconditionally. There's no way to target a cross-cutting config at a specific step (or set of steps) without knowing the cog type. This feature enables:

config do
  global(:my_step) { async! }                    # target by exact name
  global(/^api_/) { abort_on_failure! }          # target by pattern
  global { working_directory("/tmp") }           # bare (existing behavior)
end

Implementation

Approach: Structural Mimicry — mirrors the proven 3-variable pattern already used by cog-type blocks.

Storage

Adds two new instance variables alongside the existing @global_config:

Variable	Type	Purpose
@global_config	Cog::Config	Bare global { } (unchanged)
@global_regexp_configs	Hash{Regexp => Cog::Config}	global(/pattern/) { }
@global_name_configs	Hash{Symbol => Cog::Config}	global(:name) { }

Merge Cascade (7 tiers)

The config_for(type, name) method now resolves configuration in this priority order (lowest → highest):

Priority	Tier	Example
1 (lowest)	Global bare	global { }
2	Global regexp	global(/pattern/) { }
3	Global name	global(:step_name) { }
4	Cog-type general	agent { }
5	Cog-type regexp	agent(/pattern/) { }
6	Cog-type name	agent(:step_name) { }
7 (highest)	Inline YAML	Step-level YAML config

This preserves the invariant that cog-specific blocks always override globals.

Files Changed

• lib/roast/config_manager.rb — new storage, expanded bind_global/on_global, updated config_for
• sorbet/rbi/shims/lib/roast/config_context.rbi — updated type signature + docs for global
• test/roast/config_manager_test.rb — 8 new tests covering all specifier combinations

Drive-by

Replaced a vestigial instance_variable_get(:@values) with the public .values accessor.

Test Plan

All 1188 existing tests pass. 8 new tests cover:

• global(:name) exact match
• global(/regexp/) pattern match
• global(:name) skipped when name is nil
• Multiple matching regexps (insertion order)
• Global name below cog-type general in cascade
• Cog-specific override of global specifier
• Duplicate global(:name) accumulation
• Workflow params accessible inside global(:name) blocks