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[Lightning11wins]

Changes extracted from #85. Should not affect logic. Review should be very easy.

[greptile-apps]

Greptile Summary

This PR adds clarifying comments to two header files — datatypes.h and qprintf.h — and updates both copyright years to 2026. No logic is changed. The added comments accurately reflect how the fields and function pointer are used throughout the codebase.

Confidence Score: 5/5

Pure documentation/comment additions with no logic changes; safe to merge.

All added comments were verified against codebase usage sites (tm_year assignment, +1900 display adjustment, 0-based month storage, grow_fn call sites). No logic is modified, so there is no risk of runtime regression.

No files require special attention.

Important Files Changed

Filename	Overview
centrallix-lib/include/datatypes.h	Adds 0-based/1900-based annotations to all DateTime.Part bitfields and a NOT seconds since the epoch! note on Value; copyright updated to 2026. All annotations verified correct against codebase usage.
centrallix-lib/include/qprintf.h	Adds a Doxygen-style block comment documenting qpf_grow_fn_t parameter names and semantics; parameter names added to the typedef signature; copyright updated to 2026. Verified correct against implementation call sites.

Class Diagram

%%{init: {'theme': 'neutral'}}%%
classDiagram
    class DateTime {
        <<union>>
        +long long Value
    }
    class Part {
        <<struct>>
        +unsigned int Second : 6
        +unsigned int Minute : 6
        +unsigned int Hour : 5
        +unsigned int Day : 5
        +unsigned int Month : 4
        +unsigned int Year : 12
    }
    note for Part "Second, Minute, Hour, Day, Month: 0-based\nMonth: 0=January, 1=February\nYear: 1900-based (102 = 2002)\nValue: NOT seconds since the epoch"
    DateTime *-- Part : contains

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_{Reviews (3): Last reviewed commit: "Update copywrite notice in modified file..." | Re-trigger Greptile}

[Lightning11wins]

@greptileai Please re-review this PR and let me know if you have any other comments, or let me know if the PR is ready to merge.

[Lightning11wins]

PR cleared for human review.