Add fault storm script and debounce demo config

[mfaferek93]

Summary

Add the fault storm injector script and debounce mode configuration used in the Article 3 demo ("Your Robot's Fault Log Is a Haystack"). These files are needed for the "Try it yourself" section of the article, which links to fault_storm.py via raw GitHub URL.

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Proposed solution

New files

• demos/turtlebot3_integration/scripts/fault_storm.py - Injects 9 noise faults (1 report each) + 1 real fault (MOTOR_OVERHEAT, 5 sustained reports). With threshold=0 all 10 confirm; with threshold=-3 only MOTOR_OVERHEAT confirms.
• demos/turtlebot3_integration/config/medkit_params_debounce.yaml - Fault manager config with confirmation_threshold: -3, healing_enabled: true
• demos/turtlebot3_integration/docker-compose.article3.yml - Compose override that mounts debounce config
• demos/turtlebot3_integration/run-demo-debounce.sh - Convenience script to run demo in debounce mode

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