refactor: complete v1.0 simplification by removing all legacy inputs

- Remove all backward compatibility for v1.0 simplification
- Remove 10 legacy inputs from base-action/action.yml
- Remove 9 legacy inputs from main action.yml
- Simplify ClaudeOptions type to just timeoutMinutes and claudeArgs
- Remove all legacy option handling from prepareRunConfig
- Update tests to remove references to deleted fields
- Remove obsolete test file github/context.test.ts
- Clean up types to remove customInstructions, allowedTools, disallowedTools

Users now use claudeArgs exclusively for CLI control.

test/mockContext.ts

@@ -15,16 +15,8 @@ const defaultInputs = {
   triggerPhrase: "/claude",
   assigneeTrigger: "",
   labelTrigger: "",
-  anthropicModel: "claude-3-7-sonnet-20250219",
-  allowedTools: [] as string[],
-  disallowedTools: [] as string[],
-  customInstructions: "",
-  useBedrock: false,
-  useVertex: false,
-  timeoutMinutes: 30,
   branchPrefix: "claude/",
   useStickyComment: false,
-  additionalPermissions: new Map<string, string>(),
   useCommitSigning: false,
 };