docs: simplify OS detection in tool plugin development

[jdx]

Summary

Simplifies OS detection in the tool plugin development documentation by using the RUNTIME object provided by vfox/mise instead of complex manual detection patterns.

Changes

• Replace complex OS detection using package.config:sub(1,1) and os.capture("uname") with the simpler RUNTIME.osType
• Replace architecture detection using shell commands with RUNTIME.archType
• Update all examples to use the cleaner approach
• Add documentation about the RUNTIME object properties

Benefits

The new approach:

• Eliminates dependency on non-standard os.capture() function
• Removes need for shell command execution
• Provides consistent, reliable platform detection
• Makes plugin code cleaner and easier to understand
• Works consistently across all platforms (Windows, Linux, macOS)

Example

Before:

if package.config:sub(1,1) == '\\' then
    return "win"
else
    local os_name = os.capture("uname"):lower()
    if os_name:find("darwin") then
        return "darwin"
    else
        return "linux"
    end
end

After:

local os = RUNTIME.osType:lower()
if os == "windows" then
    return "win"
elseif os == "darwin" then
    return "darwin"
else
    return "linux"
end

🤖 Generated with Claude Code

[Copilot]

Pull Request Overview

This PR simplifies OS detection in the tool plugin development documentation by replacing complex manual platform detection with the built-in RUNTIME object provided by vfox/mise.

• Replaces manual OS detection using package.config:sub(1,1) and os.capture("uname") with RUNTIME.osType
• Replaces architecture detection using shell commands with RUNTIME.archType
• Adds documentation about the RUNTIME object properties and their values

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[Copilot]

Inconsistent OS name casing. Use lowercase 'windows' for consistency with other OS checks in the file (line 280, 356, 407, 438).

[Copilot]

Inconsistent OS name casing. Use lowercase 'windows' for consistency with other OS checks in the file (line 280, 356, 407).

[Copilot]

Inconsistent OS name casing. Use lowercase 'windows' for consistency with other OS checks in the file.

Suggested change

	return RUNTIME.osType == "Windows"
	return RUNTIME.osType == "windows"

[Copilot]

Inconsistent OS name casing. Use lowercase 'windows' and 'darwin' for consistency with other OS checks in the file.

[Copilot]

Inconsistent OS name casing. Use lowercase 'windows' and 'darwin' for consistency with other OS checks in the file.

[Copilot]

Inconsistent OS name casing. Use lowercase 'darwin' for consistency with other OS checks in the file.

Suggested change

	if RUNTIME.osType == "Darwin" then
	if RUNTIME.osType == "darwin" then

[github-actions]

Hyperfine Performance

mise x -- echo

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
mise-2025.9.9 x -- echo	19.5 ± 0.6	18.9	23.0	1.00
mise x -- echo	19.5 ± 0.7	18.7	25.7	1.00 ± 0.05

mise env

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
mise-2025.9.9 env	18.7 ± 0.3	18.0	22.6	1.00
mise env	18.8 ± 0.5	18.3	23.6	1.01 ± 0.03

mise hook-env

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
mise-2025.9.9 hook-env	18.3 ± 0.3	17.8	22.1	1.00
mise hook-env	18.5 ± 0.8	17.8	29.5	1.01 ± 0.05

mise ls

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
mise-2025.9.9 ls	16.3 ± 0.4	15.8	18.0	1.00
mise ls	16.4 ± 0.4	15.8	18.0	1.01 ± 0.03

xtasks/test/perf

Command	mise-2025.9.9	mise	Variance
install (cached)	167ms	✅ 103ms	+62%
ls (cached)	63ms	63ms	+0%
bin-paths (cached)	69ms	69ms	+0%
task-ls (cached)	470ms	477ms	-1%

✅ Performance improvement: install cached is 62%