docs: update build output paths from bin/ to dist/

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: magifd2

BUILD.md

@@ -13,7 +13,7 @@
 ## Build
 
 ```bash
-make build       # current platform → ./splunk-cli
+make build       # current platform → dist/splunk-cli
 make build-all   # cross-compile → dist/
 make clean       # remove artifacts
 ```

CLAUDE.md

@@ -7,7 +7,7 @@ Series and org conventions: see `../CONVENTIONS.md` and
 ## Architecture
 
 ```
-cmd/splunk-cli/main.go    Entry point — injects version, calls cmd.Execute()
+main.go                   Entry point — injects version, calls cmd.Execute()
 cmd/
   root.go                 Cobra root command, persistent flags, config loading
   common.go               Shared helpers (getSPL)