feat: Import 35+ skills, merge duplicates, add openclaw installer

Major updates:
- Added 35+ new skills from awesome-opencode-skills and antigravity repos
- Merged SEO skills into seo-master
- Merged architecture skills into architecture
- Merged security skills into security-auditor and security-coder
- Merged testing skills into testing-master and testing-patterns
- Merged pentesting skills into pentesting
- Renamed website-creator to thai-frontend-dev
- Replaced skill-creator with github version
- Removed Chutes references (use MiniMax API instead)
- Added install-openclaw-skills.sh for cross-platform installation
- Updated .env.example with MiniMax API credentials

skills/minimax-xlsx/templates/minimal_xlsx/xl/sharedStrings.xml

@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<!--
+  sharedStrings.xml — The shared string table.
+
+  All text values in cells use this table. Instead of storing text directly
+  in the cell, each text string is stored here once, and cells reference it
+  by 0-based index:
+
+      <c r="A1" t="s"><v>0</v></c>  →  first string in this table
+
+  To add strings:
+  1. Append a new <si><t>Your Text</t></si> element
+  2. Increment both `count` and `uniqueCount` attributes
+  3. Use the new string's 0-based index in the cell's <v> element
+
+  Special characters in text:
+  - & → &amp;
+  - < → &lt;
+  - > → &gt;
+  - Leading/trailing spaces → use xml:space="preserve": <t xml:space="preserve"> text </t>
+
+  count         = total number of string references across the workbook
+  uniqueCount   = number of unique strings in this table
+  (They may differ if some strings are used in multiple cells)
+-->
+<sst xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main"
+     count="0" uniqueCount="0">
+  <!-- Strings will be added here. Example:
+  <si><t>Revenue</t></si>
+  <si><t>Cost of Goods Sold</t></si>
+  <si><t>Gross Profit</t></si>
+  -->
+</sst>