chore: prepare v1.0.0 release

- Add CONTRIBUTING.md with semver and conventional commits specs
- Add LICENSE (MIT)
- Add .editorconfig
- Update README.md to reflect current feature set and project structure
- Upgrade Go to 1.26.1
- Fix code quality issues:
  - Remove unused constant magicReadSize (analyze.go)
  - Remove unused function bytesToFloat32 (showtints)
  - Remove dead code in decompressBC (texconv)
  - Add error check for f.Seek in decodeDDS (texconv)
  - Remove redundant max() helper (texconv, builtin since Go 1.21)
- Update Makefile: test all packages, install all CLI tools
- Update .gitignore for build artifacts and working files
- Remove stale CHECKLIST.md

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: thesprockee

.editorconfig

@@ -0,0 +1,21 @@
+root = true
+
+[*]
+end_of_line = lf
+insert_final_newline = true
+charset = utf-8
+trim_trailing_whitespace = true
+
+[*.go]
+indent_style = tab
+indent_size = 4
+
+[*.{md,yml,yaml}]
+indent_style = space
+indent_size = 2
+
+[Makefile]
+indent_style = tab
+
+[go.{mod,sum}]
+indent_style = tab

.gitignore

@@ -1,44 +1,54 @@
-# If you prefer the allow list template instead of the deny list, see community template:
-# https://github.com/github/gitignore/blob/main/community/Golang/Go.AllowList.gitignore
-#
-# Binaries for programs and plugins
+# Go binaries and build artifacts
 *.exe
 *.exe~
 *.dll
 *.so
 *.dylib
-
-# Test binary, built with `go test -c`
 *.test
+*.o
+bin/
 
-# Code coverage profiles and other test artifacts
+# Coverage and profiling
 *.out
 coverage.*
 *.coverprofile
 profile.cov
 
-# Dependency directories (remove the comment below to include it)
-# vendor/
-
-# Go workspace file
+# Go workspace
 go.work
 go.work.sum
 
-# env file
+# Environment
 .env
 
 # Editor/IDE
-# .idea/
-# .vscode/
-
-
+.idea/
+.vscode/
+*.swp
+*~
+
+# Project-specific build outputs (untracked binaries built by make)
+/evrtools
+/showtints
+/texconv
+/symhash
+/buildwordlist
+/listtints
+
+# Game data (symlinked or copied locally for testing)
+_data
+ready-at-dawn-echo-arena
+
+# Working directories
 Editing/
 debugging/
 manifests/
 unusual/
 norm/
-*.exe
-*.json
 output/
 /extracted/
-bin/
+
+# Scratch files
+filelist*.txt
+filelist*.xtt
+*.json