chore: archive v1.0 milestone — MVP shipped

4 phases, 18 plans, 24/24 requirements, 98 tests GREEN.
Archived ROADMAP + REQUIREMENTS to milestones/. ROADMAP collapsed.
PROJECT.md evolved with validated requirements and key decisions.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.planning/RETROSPECTIVE.md

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+# Project Retrospective
+
+*A living document updated after each milestone. Lessons feed forward into future planning.*
+
+## Milestone: v1.0 — MVP
+
+**Shipped:** 2026-03-27
+**Phases:** 4 | **Plans:** 18 | **Timeline:** 2 days
+
+### What Was Built
+- Backend Schema Registry as single source of truth driving form rendering, Zod validation, and config generation for 3 backends
+- 4 pure generator functions (rclone.conf, Intune install/detection, RMM script) with 61 tests and strict PowerShell encoding/path requirements
+- 4-step multi-step wizard (backend selection → config → deployment options → review/download) with full back-navigation
+- Review and download layer: live preview, security gate, individual file downloads, ZIP bundle, clipboard copy
+
+### What Worked
+- **Inside-out build order** (foundation → generators → wizard UI → download layer): front-loaded high-risk correctness work (PowerShell encoding, SYSTEM-context paths, credential handling) before any UI existed — each phase was independently verifiable
+- **Wave 0 TDD with `expect.fail` stubs**: defining the API contract in RED before implementation forced explicit interface design and caught integration issues upfront; named failure messages made debugging fast
+- **BACKEND_REGISTRY as single source of truth**: zero field-name duplication between form rendering, Zod schemas, and config generation — no drift possible across phases
+- **useReducer + Context API with no external state lib**: sufficient for a 4-step wizard, kept bundle lean
+
+### What Was Inefficient
+- **scriptTargets collected but never consumed**: `DeploymentStep` dispatches `scriptTargets` but `ReviewStep` ignores it — all output blocks render unconditionally. This was knowable at Phase 2 design time but deferred to v1.1 as tech debt
+- **BACKENDS constant hardcoded in BackendSelectionStep**: adding to BACKEND_REGISTRY does not surface in UI — a maintainability gap that was an obvious fix but left unaddressed
+- **ReviewStep missing Back button**: UX inconsistency with all other steps — a trivial add that was missed
+
+### Patterns Established
+- Wave 0 TDD pattern: stub all requirement behaviors RED before any implementation — use `expect.fail('not yet implemented')` not import errors
+- Embed requirement IDs in test describe blocks (WIZD-01, BACK-02, etc.) for direct test-to-requirement traceability
+- Generator functions self-contained: `buildRcloneConfContent` duplicated inline in rmm-script.ts to avoid circular dependency risk
+- INITIAL_STATE defaults to both targets selected — users deselect rather than discover
+
+### Key Lessons
+1. **Define data flow end-to-end before implementing any step**: the `scriptTargets` disconnect would have been caught if the full data flow (DeploymentStep → state → ReviewStep) had been traced before Phase 4 started
+2. **Registry-driven UI is strictly better than hardcoded lists**: the BACKEND_REGISTRY pattern proved its value — extending it for the UI selector should have been done at the same time
+3. **Inside-out build order works well for correctness-heavy tools**: generator correctness (PowerShell encoding edge cases) was much easier to verify without UI noise
+
+### Cost Observations
+- Sessions: ~6 (4 execution phases + planning + verification)
+- Notable: Pure frontend with no external API calls kept the scope tight — all phases parallelized within themselves
+
+---
+
+## Cross-Milestone Trends
+
+### Process Evolution
+
+| Milestone | Phases | Plans | Key Change |
+|-----------|--------|-------|------------|
+| v1.0 | 4 | 18 | Wave 0 TDD pattern established; inside-out build order validated |
+
+### Cumulative Quality
+
+| Milestone | Tests | Notes |
+|-----------|-------|-------|
+| v1.0 | 98 (12 files) | 24/24 requirements satisfied, 5/5 E2E flows |
+
+### Top Lessons (Verified Across Milestones)
+
+1. Single source of truth (BACKEND_REGISTRY) eliminates entire classes of drift bugs
+2. Wave 0 TDD stubs are worth the upfront cost — they define the contract and make RED→GREEN progress visible