fix(ci): resolve release pipeline conflicts and clean repo structure

- Delete conflicting .releaserc.json (keep release.config.cjs as single source)
- Fix repo URL from Draculabo/AntigravityManager to evandrodevbr/GeminiNexus
- Fix @semantic-release/git to commit pnpm-lock.yaml (not package-lock.json)
- Normalize Node.js version to 20 across all workflows
- Add packageManager field to package.json for pnpm consistency
- Update AGENTS.md: npm -> pnpm (18 references)
- Update .gitignore: add tools/, thoughts/, binaries, one-shot scripts

.gitignore

@@ -125,4 +125,32 @@ cli/aliases.json
 accounts_backup.json
 
 # Bun lock file
-bun.lock
+bun.lock
+
+# Build tools (installed via CI)
+tools/
+*.zip
+
+# AI agent session data
+thoughts/
+.impeccable.md
+CLAUDE.md
+
+# One-shot scripts (already applied)
+fix-ts.js
+patch-proxy.js
+patch-settings.js
+rename-deep.js
+test-process.ts
+
+# Legacy CLI launchers
+agm.bat
+run_cli.bat
+
+# Nix (not used)
+flake.nix
+flake.lock
+
+# Planning/spec data
+.planning/
+openspec/