Migrate generic guides from ppds-demo

[joshsmithxrm]

Summary

Migrate universally applicable guides from ppds-demo/docs/ to ppds-docs.

Scope Decision

Stays in ppds-demo (demo-specific):

• ENVIRONMENT_SETUP_GUIDE.md
• LOCAL_DEVELOPMENT_GUIDE.md
• GETTING_STARTED_GUIDE.md
• SOLUTION_STRUCTURE_REFERENCE.md
• PLUGIN_COMPONENTS_REFERENCE.md
• WEBRESOURCE_PATTERNS.md

Migrate to ppds-docs (generic knowledge):

Source	Destination	Notes
reference/PAC_CLI_REFERENCE.md	reference/cli/pac-cli.md	PAC CLI is universal
reference/TESTING_PATTERNS.md	guides/testing-patterns.md	Testing applies broadly
strategy/BRANCHING_STRATEGY.md	guides/branching-strategy.md	Git strategy is universal
strategy/PIPELINE_STRATEGY.md	alm/pipeline-strategy.md	ALM-related

Tasks

• Review each file for demo-specific content
• Adapt/generalize where needed
• Add Docusaurus frontmatter
• Update sidebars.ts
• Verify build passes

Priority: Low

Nice to have, not blocking.