Refactor to modular app factory architecture

- Replace 6847-line monolithic server.py with 26-line entry point
- All routes now in app/routers/ using Jinja2 templates
- Add plan_node.html template for step details
- Add plan node route to runs router with cache_id lookup
- Backup old server as server_legacy.py

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/routers/runs.py

@@ -309,6 +309,110 @@ async def run_artifacts(
     )
 
 
+@router.get("/{run_id}/plan/node/{cache_id}", response_class=HTMLResponse)
+async def plan_node_detail(
+    run_id: str,
+    cache_id: str,
+    request: Request,
+    run_service: RunService = Depends(get_run_service),
+):
+    """HTMX partial: Get plan node detail by cache_id."""
+    from ..services.auth_service import AuthService
+    from artdag_common import render_fragment
+
+    auth_service = AuthService(get_redis_client())
+    ctx = auth_service.get_user_from_cookie(request)
+
+    if not ctx:
+        return HTMLResponse('<p class="text-red-400">Login required</p>', status_code=401)
+
+    run = await run_service.get_run(run_id)
+    if not run:
+        return HTMLResponse('<p class="text-red-400">Run not found</p>', status_code=404)
+
+    plan = await run_service.get_run_plan(run_id)
+    if not plan:
+        return HTMLResponse('<p class="text-gray-400">Plan not found</p>')
+
+    # Build lookups
+    steps_by_cache_id = {}
+    steps_by_step_id = {}
+    for s in plan.get("steps", []):
+        if s.get("cache_id"):
+            steps_by_cache_id[s["cache_id"]] = s
+        if s.get("step_id"):
+            steps_by_step_id[s["step_id"]] = s
+
+    step = steps_by_cache_id.get(cache_id)
+    if not step:
+        return HTMLResponse(f'<p class="text-gray-400">Step not found</p>')
+
+    cache_manager = get_cache_manager()
+
+    # Node colors
+    node_colors = {
+        "SOURCE": "#3b82f6", "EFFECT": "#22c55e", "OUTPUT": "#a855f7",
+        "ANALYSIS": "#f59e0b", "_LIST": "#6366f1", "default": "#6b7280"
+    }
+    node_color = node_colors.get(step.get("node_type", "EFFECT"), node_colors["default"])
+
+    # Check cache status
+    has_cached = cache_manager.has_content(cache_id) if cache_id else False
+
+    # Determine output media type
+    output_media_type = None
+    output_preview = False
+    if has_cached:
+        cache_path = cache_manager.get_content_path(cache_id)
+        if cache_path:
+            output_media_type = run_service.detect_media_type(cache_path)
+            output_preview = output_media_type in ('video', 'image', 'audio')
+
+    # Check for IPFS CID
+    ipfs_cid = None
+    if run.step_results:
+        res = run.step_results.get(step.get("step_id"))
+        if isinstance(res, dict) and res.get("cid"):
+            ipfs_cid = res["cid"]
+
+    # Build input previews
+    inputs = []
+    for inp_step_id in step.get("input_steps", []):
+        inp_step = steps_by_step_id.get(inp_step_id)
+        if inp_step:
+            inp_cache_id = inp_step.get("cache_id", "")
+            inp_has_cached = cache_manager.has_content(inp_cache_id) if inp_cache_id else False
+            inp_media_type = None
+            if inp_has_cached:
+                inp_path = cache_manager.get_content_path(inp_cache_id)
+                if inp_path:
+                    inp_media_type = run_service.detect_media_type(inp_path)
+
+            inputs.append({
+                "name": inp_step.get("name", inp_step_id[:12]),
+                "cache_id": inp_cache_id,
+                "media_type": inp_media_type,
+                "has_cached": inp_has_cached,
+            })
+
+    status = "cached" if (has_cached or ipfs_cid) else ("completed" if run.status == "completed" else "pending")
+
+    templates = get_templates(request)
+    return HTMLResponse(render_fragment(templates, "runs/plan_node.html",
+        step=step,
+        cache_id=cache_id,
+        node_color=node_color,
+        status=status,
+        has_cached=has_cached,
+        output_preview=output_preview,
+        output_media_type=output_media_type,
+        ipfs_cid=ipfs_cid,
+        ipfs_gateway="https://ipfs.io/ipfs",
+        inputs=inputs,
+        config=step.get("config", {}),
+    ))
+
+
 @router.delete("/{run_id}/ui", response_class=HTMLResponse)
 async def ui_discard_run(
     run_id: str,

app/templates/runs/plan_node.html

@@ -0,0 +1,99 @@
+{# Plan node detail panel - loaded via HTMX #}
+{% set status_color = 'green' if status in ('cached', 'completed') else 'yellow' %}
+
+<div class="flex justify-between items-start mb-4">
+    <div>
+        <h4 class="text-lg font-semibold text-white">{{ step.name or step.step_id[:20] }}</h4>
+        <div class="flex items-center gap-2 mt-1">
+            <span class="px-2 py-0.5 rounded text-xs text-white" style="background-color: {{ node_color }}">
+                {{ step.node_type or 'EFFECT' }}
+            </span>
+            <span class="text-{{ status_color }}-400 text-xs">{{ status }}</span>
+            <span class="text-gray-500 text-xs">Level {{ step.level or 0 }}</span>
+        </div>
+    </div>
+    <button onclick="closeNodeDetail()" class="text-gray-400 hover:text-white p-1">
+        <svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+            <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M6 18L18 6M6 6l12 12"/>
+        </svg>
+    </button>
+</div>
+
+{# Output preview #}
+{% if output_preview %}
+<div class="mb-4">
+    <h5 class="text-sm font-medium text-gray-400 mb-2">Output</h5>
+    {% if output_media_type == 'video' %}
+    <video src="/cache/{{ cache_id }}/raw" controls muted class="w-full max-h-48 rounded-lg"></video>
+    {% elif output_media_type == 'image' %}
+    <img src="/cache/{{ cache_id }}/raw" class="w-full max-h-48 rounded-lg object-contain">
+    {% elif output_media_type == 'audio' %}
+    <audio src="/cache/{{ cache_id }}/raw" controls class="w-full"></audio>
+    {% endif %}
+</div>
+{% elif ipfs_cid %}
+<div class="mb-4">
+    <h5 class="text-sm font-medium text-gray-400 mb-2">Output (IPFS)</h5>
+    <video src="{{ ipfs_gateway }}/{{ ipfs_cid }}" controls muted class="w-full max-h-48 rounded-lg"></video>
+</div>
+{% endif %}
+
+{# Output link #}
+{% if ipfs_cid %}
+<a href="/ipfs/{{ ipfs_cid }}" class="flex items-center justify-between bg-gray-800 rounded p-2 hover:bg-gray-700 transition-colors text-xs mb-4">
+    <span class="font-mono text-gray-300 truncate">{{ ipfs_cid[:24] }}...</span>
+    <span class="px-2 py-1 bg-blue-600 text-white rounded ml-2">View</span>
+</a>
+{% elif has_cached and cache_id %}
+<a href="/cache/{{ cache_id }}" class="flex items-center justify-between bg-gray-800 rounded p-2 hover:bg-gray-700 transition-colors text-xs mb-4">
+    <span class="font-mono text-gray-300 truncate">{{ cache_id[:24] }}...</span>
+    <span class="px-2 py-1 bg-blue-600 text-white rounded ml-2">View</span>
+</a>
+{% endif %}
+
+{# Input media previews #}
+{% if inputs %}
+<div class="mt-4">
+    <h5 class="text-sm font-medium text-gray-400 mb-2">Inputs ({{ inputs|length }})</h5>
+    <div class="grid grid-cols-2 gap-2">
+        {% for inp in inputs %}
+        <a href="/cache/{{ inp.cache_id }}" class="block bg-gray-800 rounded-lg overflow-hidden hover:bg-gray-700 transition-colors">
+            {% if inp.media_type == 'video' %}
+            <video src="/cache/{{ inp.cache_id }}/raw" class="w-full h-20 object-cover rounded-t" muted></video>
+            {% elif inp.media_type == 'image' %}
+            <img src="/cache/{{ inp.cache_id }}/raw" class="w-full h-20 object-cover rounded-t">
+            {% else %}
+            <div class="w-full h-20 bg-gray-700 rounded-t flex items-center justify-center text-xs text-gray-400">
+                {{ inp.media_type or 'File' }}
+            </div>
+            {% endif %}
+            <div class="p-2">
+                <div class="text-xs text-white truncate">{{ inp.name }}</div>
+                <div class="text-xs text-gray-500 font-mono truncate">{{ inp.cache_id[:12] }}...</div>
+            </div>
+        </a>
+        {% endfor %}
+    </div>
+</div>
+{% endif %}
+
+{# Parameters/Config #}
+{% if config %}
+<div class="mt-4">
+    <h5 class="text-sm font-medium text-gray-400 mb-2">Parameters</h5>
+    <div class="bg-gray-800 rounded p-3 text-xs space-y-1">
+        {% for key, value in config.items() %}
+        <div class="flex justify-between">
+            <span class="text-gray-400">{{ key }}:</span>
+            <span class="text-white">{{ value if value is string else value|tojson }}</span>
+        </div>
+        {% endfor %}
+    </div>
+</div>
+{% endif %}
+
+{# Metadata #}
+<div class="mt-4 text-xs text-gray-500 space-y-1">
+    <div><span class="text-gray-400">Step ID:</span> <span class="font-mono">{{ step.step_id[:32] }}...</span></div>
+    <div><span class="text-gray-400">Cache ID:</span> <span class="font-mono">{{ cache_id[:32] }}...</span></div>
+</div>