Add more Gemini model aliases including :gemini and generation-specific aliases

Author: Bruce Hauman

src/clojure_mcp/agent/langchain/model.clj

@@ -284,13 +284,20 @@
    :sonnet-reasoning  :anthropic/claude-sonnet-4-6-reasoning
    :opus-reasoning    :anthropic/claude-opus-4-6-reasoning
    ;; Google aliases - latest points to 3.1
+   :gemini    :google/gemini-3-1-pro
+   :gemini-flash :google/gemini-3-1-flash-lite
    :flash     :google/gemini-3-1-flash-lite
    :flash-lite :google/gemini-3-1-flash-lite
    :gemini-pro :google/gemini-3-1-pro
+   ;; Google 3.x aliases
    :gemini-3-1-pro :google/gemini-3-1-pro
    :gemini-3-1-flash-lite :google/gemini-3-1-flash-lite
    :gemini-3-flash :google/gemini-3-flash
    :gemini-3-pro :google/gemini-3-pro
+   ;; Google 2.5 aliases
+   :gemini-2-5-flash :google/gemini-2-5-flash
+   :gemini-2-5-pro :google/gemini-2-5-pro
+   :gemini-2-5-flash-lite :google/gemini-2-5-flash-lite
    :flash-reasoning  :google/gemini-2-5-flash-reasoning
    :gemini-pro-reasoning :google/gemini-2-5-pro-reasoning
    ;; OpenAI aliases