docs: restructure docs — eliminate v3- prefix, merge findings, create decisions.md

Merge v3-task_plan.md content into architecture.md (data model, layout system,
keyboard shortcuts) and new decisions.md (22-entry categorized decisions log).
Merge v3-findings.md into unified findings.md (16 sections covering all research).
Move progress logs to progress/ subdirectory (v2.md, v3.md, v2-archive.md).
Rename v3-release-notes.md to release-notes.md. Update all cross-references.
Delete v3-task_plan.md and v3-findings.md (content fully incorporated).

docs/v3-release-notes.md

@@ -1,110 +0,0 @@
-# BTerminal v3.0 Release Notes
-
-## Mission Control — Multi-Project AI Agent Orchestration
-
-BTerminal v3.0 is a ground-up redesign of the terminal interface, built for managing multiple AI agent sessions across multiple projects simultaneously. The Mission Control dashboard replaces the single-pane terminal with a full orchestration workspace.
-
-### What's New
-
-**Mission Control Dashboard**
-- VSCode-style layout: icon sidebar + expandable settings drawer + project grid + status bar
-- Per-project boxes with 11 tab types (Model, Docs, Context, Files, SSH, Memory, Metrics, Tasks, Architecture, Selenium, Tests)
-- Command palette (Ctrl+K) with 18+ commands across 6 categories
-- Keyboard-first navigation: Alt+1-5 project jump, Ctrl+H/L vi-nav, Ctrl+Shift+1-9 tab switch
-- 17 themes in 3 groups (Catppuccin, Editor, Deep Dark)
-
-**Multi-Agent Orchestration**
-- 4 Tier 1 management roles: Manager, Architect, Tester, Reviewer
-- btmsg: inter-agent messaging (DMs, channels, contacts ACL, heartbeats, dead letter queue)
-- bttask: kanban task board (5 columns, optimistic locking, review queue auto-notifications)
-- Agent prompt generator with role-specific workflows and tool documentation
-- Manager subagent delegation via Claude Agent SDK teams
-- Auto-wake scheduler: 3 strategies (persistent, on-demand, smart) with 6 wake signals
-
-**Multi-Provider Support**
-- Claude Code (primary), OpenAI Codex, Ollama
-- Provider-specific sidecar runners with unified message adapter layer
-- Per-project provider selection with capability-gated UI
-
-**Session Continuity**
-- SQLite persistence for agent sessions, messages, and cost tracking
-- Session anchors: preserve important turns through context compaction
-- Auto-anchoring on first compaction (observation-masked, reasoning preserved)
-- Configurable anchor budget (2K–20K tokens)
-
-**Dashboard Metrics**
-- Real-time fleet overview: running/idle/stalled counts, burn rate ($/hr)
-- Per-project health: activity state, context pressure, file conflicts, attention scoring
-- Historical sparklines for cost, tokens, turns, tools, and duration
-- Attention queue with priority-scored cards (click to focus)
-
-**File Management**
-- VSCode-style directory tree with CodeMirror 6 editor (15 language modes)
-- PDF viewer (pdfjs-dist, multi-page, zoom 0.5x–3x)
-- CSV table viewer (RFC 4180, delimiter auto-detect, sortable columns)
-- Filesystem watcher for external write conflict detection
-
-**Terminal**
-- xterm.js with Canvas addon (WebKit2GTK compatible)
-- Agent preview pane (read-only view of agent activity)
-- SSH session management (native PTY, no library required)
-- Worktree isolation per project (optional)
-
-### Production Readiness
-
-**Reliability**
-- Sidecar crash recovery: auto-restart with exponential backoff (1s–30s, 5 retries)
-- WAL checkpoint: periodic TRUNCATE every 5 minutes (sessions.db + btmsg.db)
-- Error classification: 6 types with actionable messages and retry logic
-- Optimistic locking for concurrent task board updates
-
-**Security**
-- Landlock sandbox: kernel 6.2+ filesystem restriction for sidecar processes
-- Plugin sandbox: 13 shadowed globals, strict mode, frozen API, permission-gated
-- Secrets management: system keyring (libsecret), no plaintext fallback
-- TLS support for bterminal-relay (optional `--tls-cert`/`--tls-key`)
-- Sidecar environment stripping: dual-layer (Rust + JS) credential isolation
-- Audit logging: agent events, task changes, wake events, prompt injections
-
-**Observability**
-- OpenTelemetry: tracing + OTLP export to Tempo (optional)
-- FTS5 full-text search across messages, tasks, and agent comms
-- Agent health monitoring: heartbeats, stale detection, dead letter queue
-- Desktop + in-app notifications with history
-
-### Multi-Machine (Early Access)
-
-bterminal-relay enables running agent sessions across multiple Linux machines via WebSocket. TLS encryption is supported. This feature is architecturally complete but not yet surfaced in the v3 UI — available for advanced users via the relay binary and bridges.
-
-**v3.1 roadmap:** Certificate pinning, UI integration, real-world multi-machine testing.
-
-### Test Coverage
-
-| Suite | Tests | Status |
-|-------|-------|--------|
-| Vitest (frontend) | 444 | Pass |
-| Cargo (backend) | 151 | Pass |
-| E2E (WebDriverIO) | 109 | Pass |
-| **Total** | **704** | **All passing** |
-
-### Breaking Changes from v2
-
-- Layout system replaced by workspace store (project groups)
-- Configuration moved from sessions.json to groups.json
-- App.svelte rewritten (VSCode-style sidebar replaces TilingGrid)
-- Settings moved from modal dialog to sidebar drawer tab
-
-### Requirements
-
-- Linux x86_64
-- Kernel 6.2+ recommended (for Landlock sandbox enforcement)
-- libsecret / DBUS session (for secrets management)
-- Node.js 20+ and Rust 1.77+ (build from source)
-- Claude CLI installed (`~/.local/bin/claude` or system path)
-
-### Known Limitations
-
-- Maximum 4 active xterm.js instances (WebKit2GTK memory constraint)
-- Plugin sandbox uses `new Function()` — best-effort, not a security boundary
-- Multi-machine UI not yet integrated into Mission Control
-- Agent Teams delegation requires complex prompts to trigger reliably