chore(audit): tool path resolution, config file, dead code removal, static analysis cleanup

Tool fixes:
- FileWriteTool, FileEditTool: resolve relative paths against workingDir instead of JVM cwd
- FileReadTool: remove allowedPaths restriction — reads are unrestricted
- ShellTool: add workingDir for ProcessBuilder, remove environment().clear(), fail-open when allowedExecutables empty

Config:
- Add [tools] section to config.toml: sandbox_root, working_dir, shell_allowed_executables, default_system_prompt_path
- Three-level resolution: env var > config file > hardcoded default
- OrchestrationConfig sandboxRoot and defaultSystemPromptPath now sourced from CorrexConfig
- Single defaultOrchestrationConfig in ServerModule, shared by SessionRoutes and GlobalStreamHandler

Dead code:
- Delete EventTypes.kt — orphaned string constants duplicating serialization annotations

Static analysis:
- Remove 10 unused imports across 9 files
- Remove redundant return in ReplayOrchestrator
- Remove redundant suspend from ApprovalCoordinator.handleResponse
- Fix unreachable InputMode.None branch in InputBar
- Enable full detekt rule sets in detekt.yml

detekt.yml

@@ -1,3 +1,26 @@
+build:
+  maxIssues: 999999
+
 style:
-  NewLineAtEndOfFile:
-    active: false
+  active: true
+
+complexity:
+  active: true
+
+empty-blocks:
+  active: true
+
+exceptions:
+  active: true
+
+naming:
+  active: true
+
+performance:
+  active: true
+
+potential-bugs:
+  active: true
+
+comments:
+  active: true