fix(weathermap): correct 12 rendering and config logic bugs

[somethingwithproof]

Summary

• Fix swapped overlibwidth/overlibheight values in asJS() and asJSON() for links and nodes
• Fix array_merge + array_slice($newpoints, 1) for curve-point arrays: the previous union operator dropped key 0 (the previous control point needed for the next span calculation), causing malformed curves on multi-span links
• Fix swapped preg_replace arguments in %k format handler; use preg_replace_callback with preg_quote($spec, '/') to prevent backreference expansion and dot-matches-any
• Fix $joinchar assignment: dash flag now sets '-', not ' '
• Fix $this->configFile → $this->configfile (PHP property name case)
• Fix legend drawing: all drawing coordinates inside $scale_im use local (0,0)-based coords; $boxx/$boxy are the map-level copy destination, not the draw origin
• Remove dead return 0 at top of LoadCoverage() that suppressed all file I/O; add path guard and explode count check; add matching path-traversal guard to SaveCoverage()
• Fix gdref1 hardcoded key → $scale_ref in DrawLegend_Vertical; add isset() guards on KEYTEXT[$scale_ref]
• Fix strchr != false → !== false in header injection check
• Fix iterator variable $link_name → $node_name in editor.inc.php

Test plan

• Render a map with links that have overlibwidth/overlibheight set and verify tooltip dimensions are correct
• Render a map with a multi-span curved link and verify no backwards segment appears
• Render a map with a gradient scale and verify the legend box, outline, and text render at the correct legend position (not clipped to map (0,0))
• Confirm maps with %k bandwidth formatting display correct values
• Load and save a coverage file; verify file is read and written within the plugin base directory
• Open editor and verify node iterator does not mix up node/link names

[Copilot]

Pull request overview

This PR targets several rendering, formatting, and configuration-handling bugs in the PHP Network Weathermap plugin, primarily in map serialization, legend drawing, curve calculation, and coverage loading.

Changes:

• Corrects swapped tooltip width/height serialization for nodes and links.
• Updates formatting, config parsing, legend rendering, and coverage-loading logic.
• Renames an editor loop variable for node inheritance handling.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
lib/WeatherMapNode.class.php	Corrects node overlib width/height output in JS/JSON serialization.
lib/WeatherMapLink.class.php	Corrects link overlib width/height output in JS/JSON serialization.
lib/WeatherMap.functions.php	Updates %k/time formatting and curve point merging logic.
lib/WeatherMap.class.php	Updates legend color references, config detection, cache warning text, and coverage loading.
lib/editor.inc.php	Renames the node inheritance iterator variable.