Add Claude Code project settings and update gitignore

- Add .claude/settings.json with permission allowlist (arxiv, github, wandb, etc.), Bash access, Explanatory output style, and plan-mode default
- Ignore .claude/settings.local.json to keep personal local settings out of version control
- Ignore CLAUDE.local.md

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

.claude/settings.json

@@ -0,0 +1,38 @@
+{
+  "$schema": "https://json.schemastore.org/claude-code-settings.json",
+  "permissions": {
+    "allow": [
+      "WebSearch",
+      "WebFetch(domain:arxiv.org)",
+      "WebFetch(domain:ar5iv.labs.arxiv.org)",
+      "WebFetch(domain:github.com)",
+      "WebFetch(domain:ysu1989.github.io)",
+      "WebFetch(domain:mdcattaneo.github.io)",
+      "WebFetch(domain:medium.com)",
+      "WebFetch(domain:philipredford.com)",
+      "Bash(python3 -c \":*)",
+      "Bash(tree:*)",
+      "WebFetch(domain:neptune.ai)",
+      "WebFetch(domain:allenai.org)",
+      "WebFetch(domain:torch-foresight.readthedocs.io)",
+      "WebFetch(domain:dzlab.github.io)",
+      "WebFetch(domain:www.sigmoid.com)",
+      "WebFetch(domain:raw.githubusercontent.com)",
+      "WebFetch(domain:wandb.ai)",
+      "Skill(git:commit:*)",
+      "Skill(git:diff:*)",
+      "Skill(git:log:*)",
+      "Skill(git:show:*)",
+      "Skill(git:status:*)",
+      "Skill(git:checkout:*)",
+      "Skill(git:branch:*)",
+      "Skill(git:merge:*)",
+      "Skill(git:revert:*)",
+      "Skill(git:reset:*)"
+    ],
+    "deny": [],
+    "ask": [],
+    "defaultMode": "plan"
+  },
+  "outputStyle": "Explanatory"
+}

.gitignore

@@ -46,3 +46,6 @@ data/
 # Secrets
 .env
 *.key
+
+.claude/settings.local.json
+CLAUDE.local.md