feat: DX, extensibility, and adaptive intelligence — completes 25-feature backlog

Sprint 5 — Developer Experience (D1-D5):
- Progress indicators with emoji phase markers during orchestration
- Dry-run mode: preview workflow without executing
- /archeflow:status and /archeflow:history commands
- Onboarding skill for first-time users

Sprint 6 — Extensibility (E1-E4, A4-A6):
- Archetype composition: combine 2 archetypes into super-reviewer
- Team presets: save common team configs in .archeflow/teams/
- Hook points: pre-plan, post-check, pre-merge, post-merge custom validation
- Workflow template library: api-design, migration, dep-upgrade, docs, hotfix
- Reviewer profiles: per-project config of which reviewers run
- Explorer cache: skip redundant research on recently-explored code
- Learning from history: track archetype usefulness, recommend profile changes

skills/using-archeflow/SKILL.md

@@ -59,6 +59,40 @@ Check → Reviewers assess in parallel (approve/reject)
 Act   → All approved? Merge. Issues? Cycle back to Plan.
 ```
 
+## Progress Indicators
+
+During orchestration, emit phase markers so the user can track progress:
+
+```
+━━━ ArcheFlow: <task> ━━━━━━━━━━━━━━━━━━━
+📋 Workflow: standard (2 cycles max)
+
+🔍 [Plan] Explorer researching...        ✓ done (35s)
+🏗️ [Plan] Creator designing proposal...   ✓ done (25s, confidence: 0.8)
+⚒️ [Do]   Maker implementing...           ✓ done (90s, 4 files, 8 tests)
+🛡️ [Check] Guardian reviewing...          ✓ APPROVED
+🤔 [Check] Skeptic challenging...          ✓ APPROVED (1 INFO)
+📚 [Check] Sage reviewing...              ✓ APPROVED
+✅ [Act]  All approved — merging...        ✓ merged to main
+
+━━━ Complete: 3m 10s, 1 cycle ━━━━━━━━━━━
+```
+
+Update each line as agents complete. This gives the user real-time visibility without interrupting the flow.
+
+## Dry-Run Mode
+
+When the user asks "what would ArcheFlow do?" or uses `--dry-run`, show the plan without executing:
+
+```
+Dry run for: "Add JWT authentication"
+  Workflow: standard (2 cycles)
+  Agents:  🔍 Explorer → 🏗️ Creator → ⚒️ Maker → 🛡️ Guardian + 🤔 Skeptic + 📚 Sage
+  Est. agents: 6 per cycle, 12 max
+  Worktree: yes (isolated branch)
+  Proceed? [y/n]
+```
+
 ## Quick Start
 
 When the user gives an implementation task:
@@ -67,6 +101,27 @@ When the user gives an implementation task:
 2. If yes: load `archeflow:orchestration` skill
 3. Pick workflow (fast/standard/thorough)
 4. Execute the PDCA steps from the orchestration skill
+5. Emit progress indicators throughout (see above)
+
+## Commands
+
+| Command | What it does |
+|---------|-------------|
+| `/archeflow:orchestration` | Load and run a full PDCA orchestration |
+| `/archeflow:status` | Show current orchestration state (phase, cycle, active agents) |
+| `/archeflow:history` | Show past orchestration summaries from `.archeflow/session-log.md` |
+| `/archeflow:shadow-detection` | Load shadow monitoring rules |
+| `/archeflow:autonomous-mode` | Load autonomous/overnight session protocol |
+
+### `/archeflow:status`
+Read `.archeflow/state.json` (if exists) and report:
+- Current task, phase, and cycle
+- Active agents and their status
+- Findings so far (by severity)
+- Time elapsed
+
+### `/archeflow:history`
+Read `.archeflow/session-log.md` and show the last 5 orchestration summaries in compact format.
 
 ## Skills Reference