SIAR: Master Specification Execution Order & Dependency Matrix

Document Purpose: Authoritative, dependency-ordered execution roadmap for all 60 SIAR system specifications (33 Core Architecture Specifications + 27 UI/UX Specifications, totaling 12,893 numbered sections).
Source Directory: sys-arch/
Complements: ROADMAP.md (priority tracker) and SYS_ARCH_IMPLEMENTATION_STATUS_AND_REMAINING_SECTIONS.md.

1. Executive Summary & Ordering Principles

SIAR cannot be written in strictly numerical order (01 → 33 followed by ui-ux-01 → 27). Doing so breaks fundamental architectural dependencies:

1. Inverted Security Dependency: Spec 28 (E2EE Key Management & Privacy) encrypts data carried by transports and storage; writing strictly 01 → 33 would delay cryptographic security until after building FFI (19), embedded Linux (20), and plugin sandboxes (22, 24).
2. Inverted UI Dependency: Spec ui-ux-22 (Design System Tokens & Typography) defines the styling tokens that every view depends on; writing ui-ux-01 → 27 sequentially would build complex views like the timeline (05) and calls (07) before styling tokens even exist.
3. Joint Vertical Slices: Complex subsystems (e.g., QR pairing, notifications, search, backup, calls) require that the backend core spec and frontend UI spec be implemented together to ensure end-to-end functionality.

The 7-Milestone Flowchart

┌──────────────────────────────────────────────────────────────────────────────────┐
│ MILESTONE 1: TIER 0 — HEADLESS CORE ENGINE (Specs 01 ➔ 09)                       │
│ Sequential: Envelopes ➔ Identity ➔ Routing ➔ Outbox ➔ Blobs ➔ DTN ➔ Recovery    │
│ Status: Spec 01 Done (100%), Spec 02 Active (88% §170–§179 done), Specs 03–09 Next│
└──────────────────────────────────────┬───────────────────────────────────────────┘
                                       ▼
┌──────────────────────────────────────────────────────────────────────────────────┐
│ MILESTONE 2: TIER 1 — SECURITY & KEY MANAGEMENT BACKBONE (Spec 28)              │
│ Double Ratchet, forward secrecy, MLS group crypto, key revocation envelopes      │
└──────────────────────────────────────┬───────────────────────────────────────────┘
                                       ▼
┌──────────────────────────────────────────────────────────────────────────────────┐
│ MILESTONE 3: TIER 2 — UI DESIGN FOUNDATION & APP SHELLS                          │
│ Written Together: Tokens (ui-ux-22) + Responsive Layout (23) + App Shells (02/03)│
│ + First-Run Wizard (25) + Security Center (ui-ux-15 finish §195–§221)            │
└──────────────────────────────────────┬───────────────────────────────────────────┘
                                       ▼
┌──────────────────────────────────────────────────────────────────────────────────┐
│ MILESTONE 4: TIER 2 — CORE CHAT & SOCIAL GRAPH UI                                │
│ Written Together: Inbox (04) + Timeline (05) + Composer (06) + Contacts (08)    │
│ + Groups (09) + File Transfers (10) + Degraded States (24) + Virtualization (26) │
└──────────────────────────────────────┬───────────────────────────────────────────┘
                                       ▼
┌──────────────────────────────────────────────────────────────────────────────────┐
│ MILESTONE 5: TIER 2 — JOINT FEATURE SLICES (Core Backend + UI Together)          │
│ • QR/NFC Pairing (15 + ui-ux-12)      • Realtime Calls (29/25/26 + ui-ux-07)     │
│ • Presence & Receipts (30 + ui-ux-14) • Local Search & FTS (32 + ui-ux-11)       │
│ • Push Notifications (31 + ui-ux-13)  • Backup & Migration (33 + ui-ux-16)       │
│ • Emergency SOS (17 + ui-ux-17)       • Network Diagnostics (18 + ui-ux-20)      │
│ • Settings & Data Controls (ui-ux-18)                                            │
└──────────────────────────────────────┬───────────────────────────────────────────┘
                                       ▼
┌──────────────────────────────────────────────────────────────────────────────────┐
│ MILESTONE 6: TIER 3 — TRANSPORTS, DAEMONS & PLATFORM INFRASTRUCTURE             │
│ Relays (11) + Multipath (12) + Battery (13) + Proximity BLE/Wi-Fi Direct (14)   │
│ + Headless Daemon (16) + Embedded Linux (20) + C-ABI (19) + Android Build (27)  │
└──────────────────────────────────────┬───────────────────────────────────────────┘
                                       ▼
┌──────────────────────────────────────────────────────────────────────────────────┐
│ MILESTONE 7: TIER 4 — EXTENSIBILITY, ECOSYSTEM & QUALITY GATES (Final)           │
│ Plugin Host (24 + ui-ux-19) + WASM (22) + Extensions (21) + Interoperability (23)│
│ + Accessibility (ui-ux-21) + Fuzzing Test Suite (10) + Release Quality Gates (27)│
└──────────────────────────────────────────────────────────────────────────────────┘

2. Milestone 1: Headless Core Engine (Tier 0 — Sequential 01 → 09)

Execution Strategy: Implemented strictly sequentially. These 9 foundational crates form the underlying communications and persistence engine. Each spec directly relies on the prior spec's types and contracts.

3. Milestone 2: Security & Key Management Backbone (Tier 1)

Execution Strategy: Before expanding user interfaces or high-level network services, the End-to-End Encryption (E2EE) and key management invariants are closed. Transports and storage built in Milestone 1 operate in zero-knowledge mode over ciphertext payloads defined here.

4. Milestone 3: UI Design Foundation & App Shells (Written Together)

Execution Strategy: Frontend specifications cannot be built in numerical sequence (ui-ux-01 → 27). This milestone establishes the visual foundation, cross-platform layouts, desktop/mobile app shells, and identity management UI together.

5. Milestone 4: Core Chat & Social Graph UI (Written Together)

Execution Strategy: Implemented as a coherent frontend package on top of the Milestone 1 engine and Milestone 3 shells. Bridges siar-ui-state with the user interface.

6. Milestone 5: Joint Feature Slices (Backend Core + UI Written Together)

Execution Strategy: Specialized features implemented end-to-end. Each row represents a vertical slice: the backend core spec and its UI counterpart are coded and verified in the same development cycle.

7. Milestone 6: Transports, Daemons & Hardware Infrastructure (Tier 3)

Execution Strategy: Broadens connectivity beyond standard internet IP/QUIC into direct ad-hoc peer-to-peer radio protocols, headless relay infrastructure, and embedded system builds.

8. Milestone 7: Extensibility, Ecosystem & Quality Gates (Tier 4 — Final)

Execution Strategy: Third-party developer extensions, WebAssembly sandboxing, external chat bridges, and automated release quality gates. Intentionally reserved for the final phase to keep the core codebase lean and focused.

9. Master Specification Inventory (All 60 Documents)

Core Architecture Specs (01–33) — 6,863 Sections

UI/UX Specs (ui-ux-01–27) — 6,030 Sections

10. Current Position & Immediate Execution Steps

Current Milestone: MILESTONE 1 (Tier 0: Headless Core Engine)
Current Document : Spec 04 (04-offline-event-log-architecture.md)
Target Crate     : crates/siar-event-log
Current Status   : 10 / 95 Sections (11% Reconciled)

1. Completed Batches:
   • Spec 01: 108/108 (100%) — complete
   • Spec 02: 204/204 (100%) — complete
   • Spec 03: 200/200 (100%) — SPEC COMPLETE (19 rounds complete, 263/263 tests passing)
2. Next Step: Proceed to Step 1.4: Spec 04 (04-offline-event-log-architecture.md):
   • Append-only transactional outbox & log engine (§11+)