Describe the bug

When using gemini-2.5-flash to search for any GitHub-related data, the first search returns results successfully. However, attempting to continue the conversation (initiate a second dialogue) immediately triggers an error with a panic related to invalid memory address/nil pointer dereference.

Setup

Please complete the following information along with version numbers, if applicable.

• O Swindows10
• Shell powershell

Note: you might encounter rendering issues if your locale does not use
UTF-8 encoding. Please check your locale (locale on POSIX systems) to
see what encoding is being used by your system.

To Reproduce

Steps to reproduce the behavior:

1. Use gemini-2.5-flash to search for any GitHub-related data (e.g., repository information, code snippets)
2. Wait for the initial search results to be returned
3. Attempt to continue the conversation (e.g., ask a follow-up question related to the results)
4. See the panic error

Source Code

N/A (issue occurs with standard usage flow)

Expected behavior

The conversation should continue normally without errors when following up on GitHub search results.

Screenshots

N/A (error output provided below)

Additional context

Error message details:

panic: runtime error: invalid memory address or nil pointer dereference
...[signal 0xc0000005 code=0x0 addr=0x50 pc=0x7
:..
esc cancel·tab focus chat ·ctrl+p commands ·shift+enter newline · ctrl+c quit ·ctrl+g more
1，0x1})
/home/runner/go/pkg/mod/google.golang.org/genai@vl.19.0/chats.go:221 +0xa0
google.golang.org/genai.(*Chat
.org/genai@v1.19.0/chats.go:213 +0x17c
github.com/charmbracelet/crush/internal/llm/provider.(*geminiClient).stream.funcl(
m/provider.(*geminiClient).stream in goroutine 45
/home/runner/work/crush/crush/internal/llm/provider/gemini.go:30