feat(reflect_cpp): add reflect-cpp compile-time reflection component

[finger563]

Description

Adds a new reflect_cpp component vendoring getml/reflect-cpp v0.25.0 as a git submodule under detail/ (same pattern as serialization/alpaca). It exposes compile-time reflection over plain aggregate structs — field iteration in declaration order plus field names, no macros, no code generation.

Only the header-only reflection core is exposed (rfl/to_view.hpp and friends): the component is a pure INCLUDE_DIRS registration; reflect-cpp's compiled JSON backend (yyjson/CTRE) is never built.

This is the base of a stacked PR: the follow-up PR replaces the cdr component with a reflection-driven CDR/XCDR serialization library that uses this component as its backend.

Changes

• components/reflect_cpp/ — component (CMakeLists, manifest, README) + detail/reflect-cpp submodule @ v0.25.0
• doc/en/data/reflect_cpp.rst + index entry
• .github/workflows/upload_components.yml — registry upload entry
• suppressions.txt — exclude the vendored detail/ tree from cppcheck (matching lib/)

Notes

• Requires C++20 (default on IDF 5.2+ toolchains); manifest declares idf: >=5.2
• No example app (header-only dependency component); exercised by the cdr component's example and tests in the stacked PR

🤖 Generated with Claude Code

[github-actions]

✅Static analysis result - no issues found! ✅

[Copilot]

Pull request overview

This PR adds a new reflect_cpp component that vendors the header-only core of getml/reflect-cpp as a submodule to provide compile-time reflection utilities to other ESPP components, along with documentation and registry-upload wiring. However, it also removes the existing in-tree cdr implementation and introduces a cdr submodule without completing the migration, which leaves the repository in a build-breaking state.

Changes:

• Add components/reflect_cpp as an include-only component exposing reflect-cpp headers via a vendored submodule.
• Add Sphinx docs for reflect_cpp and link it into the data index.
• Update submodules / registry upload list / cppcheck suppressions (but the cdr change set is incomplete and breaks builds).

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
components/reflect_cpp/CMakeLists.txt	Registers reflect-cpp headers as an include-only IDF component.
components/reflect_cpp/idf_component.yml	Adds component metadata and IDF version requirement.
components/reflect_cpp/README.md	Documents reflect_cpp usage and intent.
doc/en/data/reflect_cpp.rst	Adds documentation page for the new component.
doc/en/data/index.rst	Adds reflect_cpp to the data docs toctree.
suppressions.txt	Suppresses cppcheck findings under the vendored reflect_cpp tree.
.github/workflows/upload_components.yml	Adds components/reflect_cpp to the upload list.
.gitmodules	Adds reflect-cpp submodule (and also adds a cdr submodule).
components/cdr/include/cdr.hpp	Deletes the in-tree public CDR API header (breaking change).
components/cdr/src/cdr.cpp	Deletes the in-tree CDR source stub (migration incomplete).

Suppressed comments (1)

suppressions.txt:13

• Since this PR adds a new vendored submodule at components/cdr/detail/cdr (see .gitmodules), cppcheck will likely start scanning third-party code there unless it’s also suppressed (similar to lib/* and components/reflect_cpp/detail/*). Consider adding a suppression for the new components/cdr/detail/* tree as well to keep static analysis focused on project code.

*:lib/*
*:components/reflect_cpp/detail/*

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[finger563]

Rewrote the stack to fix a staging error the review caught: the cdr submodule + old cdr header/source deletions had leaked into this base PR, which is what broke the wheel/library builds and the cdr/rtps/p4 example builds here. This PR is now purely additive (verified: no deleted or modified files vs main other than list-entry additions), so those jobs should go green on this run.

Two failures from the previous run were unrelated CI infra flakes — e.g. build (components/bmi270/example, esp32p4) failed at the Checkout repo step (submodule fetch), not compilation.

Also softened the reflect_cpp doc/README wording so nothing merged here references behavior that only lands with the stacked #704.