# Delta methodology

## Frozen window

- Start, exclusive: `2026-07-25T02:25:12Z`
- End, inclusive: `2026-07-28T18:18:41Z`
- Repositories: `pinklon/shareplane-platform`, `pinklon/shareplane-control-tower`
- Platform head at cutoff: `a031b8d1777c4a44bfeac2c3aac3a310a95ce597`
- Control Tower head at cutoff: `39b008a3b2cbbc519e785e5f9f59961bef97d090`
- Collector: `issue-191-delta-collector-v1.0.0`

The start is the exact integration timestamp of accepted Platform PR #102. That PR defines the baseline and is not part of the delta. The protected accepted-review deployment was `7fc9d281` at `2026-07-25T02:00:38Z`. Owner acceptance was recorded at `2026-07-25T02:24:08Z`.

## Inclusion and exclusion

Count each unique pull request whose GitHub `merged_at` is later than the checkpoint and no later than the cutoff. Exclude closed-unmerged PRs, drafts not merged, issues, comments, branches, Skills, Tony Brain, legacy repositories, and duplicate observations. Later merges cannot change this edition because the cutoff and repository heads are immutable inputs.

## Classification

Classification is a deterministic first-match keyword rule over the normalized GitHub PR title. PR bodies are deliberately excluded because repeated workflow and Production boundary templates would overwhelm the engineering subject of the change. Every PR receives exactly one primary plane. Later matching planes become secondary planes. Empty matches fall back to Product and semantics.

- **Deployment and security:** first match for security, access, cloudflare, deploy, production, credential, csp, private boundary, containment.
- **Authority and concurrency:** first match for authority, writer, lease, claim, concurrency, checkout, governance, contract, collision, queue.
- **Evidence and learning:** first match for evidence, receipt, validate, validation, test, telemetry, audit, learning, proof, determin.
- **Operational state:** first match for cockpit, state, status, closeout, release, convergence, observability, runtime, health.
- **Publication and experience:** first match for publish, publication, article, artifact, site, shell, layout, css, reading, route, experience, responsive.
- **Autonomous execution:** first match for agent, codex, worker, automation, autonomous, execution, orchestrat.
- **Product and semantics:** first match for semantic, product, concept, voice, thesis, meaning, candidate, intake.

Surface classification uses the same ordered first-match method: repair, receipt-only, Production, Development, infrastructure, governance, then public fallback.

## Limitations

Merged PR count is an engineering activity measure, not proof of productivity, quality, effort, labor equivalence, or business outcome. GitHub PR records provide the accepted head and merge commit identities where available. This edition does not replay merge ancestry or estimate unrecorded work.