fix(ui): use model input limit for avail tokens

Upgrade @opencode-ai/sdk to 1.2.6 and prefer v2 model limit.input when present for the session AVAIL chip; otherwise keep the existing context-window-based estimate.

package-lock.json

@@ -2809,9 +2809,9 @@
       }
     },
     "node_modules/@opencode-ai/sdk": {
-      "version": "1.1.11",
-      "resolved": "https://registry.npmjs.org/@opencode-ai/sdk/-/sdk-1.1.11.tgz",
-      "integrity": "sha512-vqdNDz8Q+4bygmDdQem6oxhU31ci4JVdoND4ZJNeCs9x6OIU6MM3ybgemGpzNkgtJDlfb4xCdrPaZZ6Sr3V1IQ==",
+      "version": "1.2.6",
+      "resolved": "https://registry.npmjs.org/@opencode-ai/sdk/-/sdk-1.2.6.tgz",
+      "integrity": "sha512-dWMF8Aku4h7fh8sw5tQ2FtbqRLbIFT8FcsukpxTird49ax7oUXP+gzqxM/VdxHjfksQvzLBjLZyMdDStc5g7xA==",
       "license": "MIT"
     },
     "node_modules/@pinojs/redact": {
@@ -12075,7 +12075,7 @@
       "dependencies": {
         "@git-diff-view/solid": "^0.0.8",
         "@kobalte/core": "0.13.11",
-        "@opencode-ai/sdk": "1.1.11",
+        "@opencode-ai/sdk": "1.2.6",
         "@solidjs/router": "^0.13.0",
         "@suid/icons-material": "^0.9.0",
         "@suid/material": "^0.19.0",