Here's a summary of everything that was changed.

Core Helper Functions (googleDocsApiHelpers.ts)

• findTextRange() -- Added optional tabId parameter. When provided, fetches with includeTabsContent: true, locates the target tab via findTabById(), and searches that tab's documentTab.body.content instead of the default document.body.content. Throws a UserError if the tab is not found.
• getParagraphRange() -- Same pattern as findTextRange(). Now accepts optional tabId and searches within the correct tab's content.
• createTable() -- Added optional tabId parameter, sets it on the location object when provided.
• insertInlineImage() -- Added optional tabId parameter, sets it on the location object when provided.

Tool Parameter Schemas (types.ts)

• ApplyTextStyleToolParameters -- Added optional tabId field.
• ApplyParagraphStyleToolParameters -- Added optional tabId field.

Tool Implementations

• applyTextStyle -- Threads tabId to both findTextRange() and buildUpdateTextStyleRequest().
• applyParagraphStyle -- Threads tabId to findTextRange(), getParagraphRange(), and buildUpdateParagraphStyleRequest().
• insertTable -- Added tabId parameter with tab existence verification, passes through to createTable().
• insertPageBreak -- Added tabId parameter with tab existence verification, sets it on the location object.
• insertImage -- Added tabId parameter with tab existence verification, passes through to insertInlineImage().

Tests (googleDocsApiHelpers.test.ts)

• findTextRange with tabId correctly searches tab-specific content
• findTextRange throws UserError for nonexistent tabId
• findTextRange without tabId does not use includeTabsContent
• getParagraphRange with tabId correctly searches tab-specific content
• getParagraphRange throws UserError for nonexistent tabId

Fixes #39, #11, and #34