Initial commit: docs, decisions, and M1 sensor core

Planning docs (SPEC, ARCHITECTURE, MODULES, ROADMAP, DECISIONS) with
decisions D1-D15 settled: RigDoctor name, Python 3 + Qt/PySide6 stack
(core/CLI/daemon stdlib-only), Ubuntu + NVIDIA first, .deb packaging,
read-only + suggestions, GUI + tray modules, stress module dropped.

First code: the M1 sensor core (stdlib-only) and a CLI.
- core engine: Reading/Sample model, Sampler, hwmon reader
- self-probing sources (NVIDIA first): nvidia-smi GPU, coretemp/k10temp
  CPU, /proc/meminfo + DDR5 SPD memory, NVMe storage
- CLI: snapshot (text/JSON), monitor, sources; record/report stubbed
- stdlib unittest smoke tests

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,17 @@
+# Python
+__pycache__/
+*.py[cod]
+.venv/
+venv/
+
+# RigDoctor runtime output
+logs/
+*.csv
+*.jsonl
+src/**/__pycache__/
+
+# Editor / OS
+.vscode/
+.idea/
+*.swp
+.DS_Store