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]>

content/root/root-02-linux-administration-networking/m04-linux-network-inspection/05-reflection.md

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+# Reflection: Five Commands, Five Answers, One Diagnosis
+
+## Reflection questions
+
+1. Which of these five commands did you already know before this module? Which was
+   genuinely new?
+2. You now have a real toolkit for Module 3's "where is the failure" question. What's still
+   missing before you'd feel fully confident diagnosing a real production networking issue?
+
+## Real Ops takeaway
+
+**Five specific commands, each answering one specific question, beat one vague instinct that
+"something's wrong with the network."** This is the exact toolkit real engineers reach for
+first, in this order, when handed an unfamiliar connectivity problem. Module 5 puts all five
+into one continuous diagnostic story; Module 6 formalizes the discipline around using them.
+
+This module is complete. Continue to the next module.
+
+## Instructor Notes
+
+**Discussion questions for a live classroom:** question 2's honest answer is usually
+"experience with real, varied failures" — a good moment to set expectations that fluency
+compounds with practice, not from one module.
+
+**Approximate timing:** 5-8 minutes live discussion; 5 minutes self-paced writing.