luci-{base,mod-system}: add support for RGB LEDs

[tmacholda]

Pull request details

Description

Add support for changing LED brightness and colors in LuCI.

The attributes (color names, maximum and current brightness, etc.) are pulled directly from sysfs (in case of using e.g. CMY instead of RGB) which might hamper translation efforts. It may be worth it to simply hard-code the color names to be RGB for this purpose.

Note: I have written very little JS code overall so there are definitely stupid mistakes in the code.

Screenshot or video of changes (if applicable)

Maintainer (preferred)

@feckert

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Tested on

OpenWrt version: openwrt 24.10 (r29199+104-d5ac5cdfb2)
LuCI version: LuCI openwrt-24.10 branch (24.297.79519~bcd13b9)
Web browser(s): Firefox 151.0.2-1

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Checklist

• This PR is not from my main or master branch 💩, but a separate branch. ✅
• Each commit has a valid ✒️ Signed-off-by: <my@email.address> row (via git commit --signoff).
• Each commit and PR title has a valid 📝 <package name>: title first line subject for packages.
• Incremented 🆙 any PKG_VERSION in the Makefile.
• (Optional) Includes what Issue it closes (e.g. openwrt/luci#issue-number).
• (Optional) Includes what it depends on (e.g. openwrt/packages#pr-number in sister repo).

[openwrt-ai]

Reviewed 2 new commits; the RGB-LED changes wire up cleanly against the in-tree backend — the new brightness and color_<channel> UCI options are read by package/base-files/files/etc/init.d/led (config_get ... color_${color} and config_get brightness), so this is not a frontend-only addition. access() on the rpcd side follows the existing existence-check pattern in the same file. One style nit inline.

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Generated by Claude Code

[tmacholda]

related to (but not dependent on) openwrt/openwrt#23670

[openwrt-ai]

Reviewed 1 new commit; no new issues found. The delta since the last review is the requested style fix (var→let/const and the missing trailing semicolons), which resolves the earlier nit.

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Generated by Claude Code