Workshop Refresh

Inner runs (artifact-only) — mandatory

Follow references/vendored/workshop/workshop-invariants.md § 3 (canonical allowed/forbidden contract) for every inner Design/Estimate run. Heroku specifics: leave phases.design and phases.estimate as "completed"; the inner Estimate skips the post-Estimate workshop offer; current_phase stays "estimate" until workshop-assemble.md.

Baseline capture (no Design yet)

When scenarios/ or scenarios/index.json is absent:

1. Compute inventory_fingerprint = SHA-256 hex of $MIGRATION_DIR/heroku-resource-inventory.json bytes.
2. Create scenarios/.
3. Copy working-tree artifacts to:
   • scenarios/scenario-001.preferences.json
   • scenarios/scenario-001.aws-design.json
   • scenarios/scenario-001.estimation-infra.json
4. Write scenarios/scenario-001.json manifest with source: "baseline", label: "baseline", fingerprints, and estimation_summary from current estimation-infra.json (projected_costs.*, complexity_tier, pricing_source.status, workshop.region_note or null).
5. Write scenarios/index.json with baseline_scenario_id / active_scenario_id = scenario-001, max_scenarios: 5.
6. Ensure preferences.workshop exists: { "active": true, "cpu_architecture": "<existing or x86_64>", "last_sheet_at": "<now>", "active_scenario_id": "scenario-001" } Write preferences back if created/updated.
7. If this invocation was baseline-only (no sheet apply), stop and return to workshop.md to present the sheet.

Apply & reprice

1. Inventory guard

Recompute inventory fingerprint. If it differs from scenarios/index.json.inventory_fingerprint, STOP:

Inventory changed since baseline. Re-run Discover before workshop reprice.

2. Stale Generate guard — already enforced at Entry, not repeated here

workshop.md § Entry step 2 (“Stale Generate/decide guard”) is the single authoritative point that detects a stale Generate/decide state (completed, in-progress, or a resolved decide-complete with run_mode set) and resets phases.generate and downstream phases to "pending". It runs before workshop-refresh.md is ever reached, on every path into this phase (Apply & reprice, Compare scenarios, or exiting workshop without touching this file at all). By the time this step runs, phases.generate has therefore already been reset if it needed to be.

That guard does NOT delete anything Generate wrote — a previous execution pack (terraform/, generation-*.json, etc.) is left on disk untouched, since files under terraform/ may carry customer edits (generate-terraform.md tells users to fill in terraform.tfvars and hand-edit baseline.tf/ variables.tf) that no filename-based rule can safely distinguish from still-pristine generated output. The Decision gate’s --mode decision validator determines “pre-execution” from .phase-status.json‘s phases.generate value, not from whether those files exist — so a stale execution pack coexisting with a fresh decision is the expected, supported state, not something this step needs to resolve.

Do not re-check phases.generate == "completed" here — a second check at this point would never fire, since Entry step 2 already reset it on this same invocation.

If workshop-refresh.md is ever invoked without having passed through workshop.md § Entry, treat that as an interpreter bug.

3. Patch preferences

Apply sheet edits to $MIGRATION_DIR/preferences.json:

• Update knob paths from the sheet.
• Set metadata.timestamp to now.
• Set workshop.active: true, workshop.last_sheet_at to now, workshop.cpu_architecture from the sheet.
• Leave non-knob fields untouched.

4. Re-run Design (inner)

Execute Design per Inner runs above against the frozen inventory + patched preferences. Overwrite $MIGRATION_DIR/aws-design.json. Do not touch inventory.

5. Re-run Estimate (inner)

Execute Estimate per Inner runs above. Overwrite $MIGRATION_DIR/estimation-infra.json. Chat note only: “Workshop reprice Estimate complete; returning to workshop loop.”

6. Snapshot new scenario

1. Allocate next id: scenario-00N where N = max existing + 1 (zero-pad 3).
2. If index.json.scenarios.length would exceed 5, before deleting: warn the user with the scenario id and label that will be evicted (oldest non-baseline), then delete that scenario’s manifest + three artifact copies and drop it from index.json.scenarios[]. Never delete baseline_scenario_id unless the user explicitly resets the workshop.
3. Copy working-tree preferences / aws-design / estimation-infra into scenarios/{id}.*.
4. Build preferences_subset: dot-paths whose values differ from scenario-001.preferences.json (workshop knobs only — region, availability, database_ha, redis_ha, compute_target.default, cost_optimization, workshop.cpu_architecture).
5. Write scenarios/{id}.json with source: "workshop", label summarizing the subset (e.g. arm64 + multi-az), fingerprints, estimation_summary (include all three monthly tiers + region_note from estimation-infra if present).
6. Update index.json: append scenario, set active_scenario_id, set preferences.workshop.active_scenario_id to match; write preferences.

7. Hand back

Return to workshop.md → run workshop-compare.md.