feat(root02): author Linux Administration & Networking

Adds all 6 ROOT 02 modules (Linux system administration, storage & filesystems, the
Networking Mental Model, Linux network inspection, DNS & HTTP, Linux troubleshooting) — 37
activities, each with a real lesson, demonstration/guided exercise, knowledge check, hands-on
Lab, and reflection. The Networking Mental Model module (M3) gets deliberately extra depth per
its "critical module" designation, with no lab by design — conceptual mastery via knowledge
check and guided exercise, matching root-05-m00's own precedent.

Adds 6 new hands-on Linux/networking scenarios plus 2 MCQs: linux-service-inspection (inspects
the platform's own real nginx without touching it — a genuinely safe, real service-inspection
target that avoids ever risking the Lab's own connectivity), linux-service-lifecycle (start/
verify/stop a fully controllable service), linux-storage-inspection, linux-network-inspection
(ip/ss/getent/curl, each framed as answering one specific diagnostic question),
linux-dns-http-diagnosis (a genuine DNS-resolves-but-wrong-port failure, diagnosed and fixed),
and linux-troubleshooting-framework (a real missing-config-file failure, resolved via the
RootNode Observe/Evidence/Hypothesis/Test/Repair/Validate/Prevent framework). All tested
end-to-end via the real scenario-validation API, including negative tests confirming they fail
when unsolved.

Wires rootnode-linux-networking-assessment (2 required + 4 random-draw scenarios) using the
existing Phase 3B assessment engine.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

scenarios/data/linux-troubleshooting-framework.json

@@ -0,0 +1,37 @@
+{
+  "id": "linux-troubleshooting-framework",
+  "title": "A Service Won't Start — Apply the Framework, Don't Just Guess",
+  "category": "Troubleshooting",
+  "isolation_type": "shared_namespace",
+  "difficulty": "Medium",
+  "type": "task",
+  "weight": 6,
+  "description": "## A Service Won't Start — Apply the Framework, Don't Just Guess\n\nA startup script at `/srv/trouble-lab/start.sh` is failing. Don't just poke at it randomly — apply OBSERVE → GATHER EVIDENCE → FORM HYPOTHESIS → TEST → REPAIR → VALIDATE → PREVENT.\n\n**Your task:**\n\n1. **Observe**: run `/srv/trouble-lab/start.sh` and note that it fails\n2. **Gather evidence**: the script's own error output tells you exactly what's missing — read it\n3. **Form a hypothesis and repair**: create whatever the error says is missing, with the correct content\n4. **Validate**: rerun the script and confirm it now succeeds AND that `/srv/trouble-lab/service.ready` is created",
+  "hints": [
+    {
+      "title": "Reading the real error",
+      "body": "Redirect both stdout and stderr to a log file, then read it — the script's failure message names the exact missing path.",
+      "command": "/srv/trouble-lab/start.sh > /srv/trouble-lab/service.log 2>&1; cat /srv/trouble-lab/service.log"
+    },
+    {
+      "title": "The fix",
+      "body": "The script expects a config file at a specific path with SOME content — any non-empty content satisfies it, since the script only checks that the file exists.",
+      "command": "mkdir -p /srv/trouble-lab/config\necho 'mode=production' > /srv/trouble-lab/config/settings.conf\n/srv/trouble-lab/start.sh"
+    }
+  ],
+  "setup_commands": [
+    { "command": "mkdir -p /srv/trouble-lab" },
+    { "command": "printf '#!/bin/bash\\nCONFIG=/srv/trouble-lab/config/settings.conf\\nif [ ! -f \"$CONFIG\" ]; then\\n  echo \"FATAL: config file not found: $CONFIG\" >&2\\n  exit 1\\nfi\\necho \"Started with config: $(cat $CONFIG)\"\\necho ready > /srv/trouble-lab/service.ready\\n' > /srv/trouble-lab/start.sh" },
+    { "command": "chmod +x /srv/trouble-lab/start.sh" }
+  ],
+  "validation": {
+    "commands": [
+      { "description": "the service now starts successfully", "command": "/srv/trouble-lab/start.sh >/dev/null 2>&1; echo $?", "expected_output": "0", "match": "exact" },
+      { "description": "the ready marker was actually created", "command": "cat /srv/trouble-lab/service.ready", "expected_output": "ready", "match": "exact" }
+    ]
+  },
+  "default_namespace": "default",
+  "teardown_commands": [
+    { "command": "rm -rf /srv/trouble-lab" }
+  ]
+}