fix: Consolidate redundant/broken gitignore node_modules entries (#204)

Remove redundant `node_modules/` entries from sub-directory .gitignore
files. The root `.gitignore` already has `**/node_modules/` which covers
all nested directories, making these per-package entries unnecessary.

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

kraiken-lib/.gitignore

@@ -1,2 +1 @@
 dist
-node_modules/

landing/.gitignore

@@ -7,7 +7,6 @@ yarn-error.log*
 pnpm-debug.log*
 lerna-debug.log*
 
-node_modules/
 .DS_Store
 dist
 dist-ssr

services/ponder/.gitignore

@@ -1,4 +1,3 @@
-node_modules/
 .ponder
 .env
 *.log

services/txnBot/.gitignore

@@ -1,5 +1,4 @@
 # Node.js specific
-node_modules/
 npm-debug.log
 yarn-error.log
 package-lock.json

web-app/.gitignore

@@ -8,7 +8,6 @@ pnpm-debug.log*
 lerna-debug.log*
 
 # Dependency directories
-node_modules/
 .pnpm-store
 
 # Build output