fix(#2376): emit absolute subagent-facing paths from init/state, convert workflow literals (#2428)

* fix(#2376): emit absolute subagent-facing init/state paths

Make init.* and state.* path fields absolute rather than cwd-relative
so subagent prompts resolve correctly regardless of working directory.
Adds intel_dir/conflicts_path/requirements_path/roadmap_path/state_path
to cmdInitIngestDocs, an absolute debug_dir to cmdStateLoad, and
replaces bare .planning/... literals in 12 workflow Agent() prompt
blocks with the absolute init-JSON path fields. Includes decoy-cwd
regression tests and realpath'd tmpdir fixtures for macOS.

Squashed rebase of the #2376 commit series onto a fresh origin/next
(previous merge ee25543a1 was against a now-stale next).

* chore(#2376): add changeset

* chore(#2376): regenerate golden fixtures + workflow size baseline

Regenerated after rebasing the absolute-path fix onto current next
(picks up #2351's run-with-timeout content in execute-phase.md too).

* fix(#2376): trim execute-phase.md redundancy to stay under the size margin

* chore(#2376): regenerate golden/size baseline after rebase onto next

gsd-core/workflows/map-codebase.md

@@ -159,7 +159,7 @@ Today's date: {date}
 
 Analyze this codebase for technology stack and external integrations.
 
-Write these documents to .planning/codebase/:
+Write these documents to {codebase_dir}/:
 - STACK.md - Languages, runtime, frameworks, dependencies, configuration
 - INTEGRATIONS.md - External APIs, databases, auth providers, webhooks
 
@@ -185,7 +185,7 @@ Today's date: {date}
 
 Analyze this codebase architecture and directory structure.
 
-Write these documents to .planning/codebase/:
+Write these documents to {codebase_dir}/:
 - ARCHITECTURE.md - Pattern, layers, data flow, abstractions, entry points
 - STRUCTURE.md - Directory layout, key locations, naming conventions
 
@@ -211,7 +211,7 @@ Today's date: {date}
 
 Analyze this codebase for coding conventions and testing patterns.
 
-Write these documents to .planning/codebase/:
+Write these documents to {codebase_dir}/:
 - CONVENTIONS.md - Code style, naming, patterns, error handling
 - TESTING.md - Framework, structure, mocking, coverage
 
@@ -237,7 +237,7 @@ Today's date: {date}
 
 Analyze this codebase for technical debt, known issues, and areas of concern.
 
-Write this document to .planning/codebase/:
+Write this document to {codebase_dir}/:
 - CONCERNS.md - Tech debt, bugs, security, performance, fragile areas
 
 IMPORTANT: Use {date} for all [YYYY-MM-DD] date placeholders in documents.