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+# Hardware
+
+## Classification
+
+Hardware / firmware workspace.
+
+## Structure Signals
+
+- `src` (4 files)
+- `(root)` (3 files)
+- `.pio` (1 files)
+
+## File Type Signals
+
+- `.gitignore` (2)
+- `.cpp` (2)
+- `.h` (2)
+- `.checksum` (1)
+- `.ini` (1)
+
+## Build And Dependency Signals
+
+| Signal | Detail |
+|---|---|
+| platformio.ini | envs=seeed_xiao_esp32s3; boards=seeed_xiao_esp32s3; frameworks=arduino |
+| README files | README.md |
+
+## Project Tree Snapshot
+
+- ._.gitignore
+- .gitignore
+- .pio/build/project.checksum
+- platformio.ini
+- src/main.cpp
+- src/nfc_types.h
+- src/security_research.cpp
+- src/security_research.h
+
+## Interpretation
+
+Treat this repo as hardware-affecting until proven otherwise. Add exact board revision, wiring, flashing command, and recovery procedure before release.