2.5 The Cornerstone - Core

Tier file - what this step includes at the Core tier. The Cornerstone is never optional at any tier.

Included

Everything in Focused, plus:

• Fuller assembly across the larger definition base (deeper IA and content model, comparison matrix, migration detail - more sections substantive, fewer carried by boilerplate)
• 90-minute playback, in person where practical
• The progress pulse runs through the chapter (as in Clarify)

Not Included (Upgrade Triggers)

• Staged assembly and multi-session playback (working team, then steering group / board) → Full.

Outputs

The Cornerstone (see cornerstone.md).