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.

src/github/context.ts

@@ -65,13 +65,9 @@ type BaseContext = {
     triggerPhrase: string;
     assigneeTrigger: string;
     labelTrigger: string;
-    allowedTools: string[];
-    disallowedTools: string[];
-    customInstructions: string;
     baseBranch?: string;
     branchPrefix: string;
     useStickyComment: boolean;
-    additionalPermissions: Map<string, string>;
     useCommitSigning: boolean;
   };
 };
@@ -115,15 +111,9 @@ export function parseGitHubContext(): GitHubContext {
       triggerPhrase: process.env.TRIGGER_PHRASE ?? "@claude",
       assigneeTrigger: process.env.ASSIGNEE_TRIGGER ?? "",
       labelTrigger: process.env.LABEL_TRIGGER ?? "",
-      allowedTools: parseMultilineInput(process.env.ALLOWED_TOOLS ?? ""),
-      disallowedTools: parseMultilineInput(process.env.DISALLOWED_TOOLS ?? ""),
-      customInstructions: process.env.CUSTOM_INSTRUCTIONS ?? "",
       baseBranch: process.env.BASE_BRANCH,
       branchPrefix: process.env.BRANCH_PREFIX ?? "claude/",
       useStickyComment: process.env.USE_STICKY_COMMENT === "true",
-      additionalPermissions: parseAdditionalPermissions(
-        process.env.ADDITIONAL_PERMISSIONS ?? "",
-      ),
       useCommitSigning: process.env.USE_COMMIT_SIGNING === "true",
     },
   };
@@ -198,33 +188,6 @@ export function parseGitHubContext(): GitHubContext {
   }
 }
 
-export function parseMultilineInput(s: string): string[] {
-  return s
-    .split(/,|[\n\r]+/)
-    .map((tool) => tool.replace(/#.+$/, ""))
-    .map((tool) => tool.trim())
-    .filter((tool) => tool.length > 0);
-}
-
-export function parseAdditionalPermissions(s: string): Map<string, string> {
-  const permissions = new Map<string, string>();
-  if (!s || !s.trim()) {
-    return permissions;
-  }
-
-  const lines = s.trim().split("\n");
-  for (const line of lines) {
-    const trimmedLine = line.trim();
-    if (trimmedLine) {
-      const [key, value] = trimmedLine.split(":").map((part) => part.trim());
-      if (key && value) {
-        permissions.set(key, value);
-      }
-    }
-  }
-  return permissions;
-}
-
 export function isIssuesEvent(
   context: GitHubContext,
 ): context is ParsedGitHubContext & { payload: IssuesEvent } {