Refresh default model IDs for current providers

Update auto-generated opencode.json defaults to model IDs that are
valid as of April 2026:

- anthropic: claude-sonnet-4-5 -> claude-sonnet-4-6
- openai:    gpt-4o (retired Apr 3 2026) -> gpt-5.4
- bedrock:   anthropic.claude-sonnet-4-5-v1 (invalid) ->
             global.anthropic.claude-sonnet-4-5-20250929-v1:0

The Bedrock ID now uses the global inference profile (no regional
10% premium) and includes the required date stamp and :0 suffix.

entrypoint-user.sh

@@ -22,7 +22,7 @@ if [ ! -f "$CONFIG_FILE" ] && [ -n "${OPENCODE_PROVIDER:-}" ]; then
       cat > "$CONFIG_FILE" <<EOF
 {
   "\$schema": "https://opencode.ai/config.json",
-  "model": "${OPENCODE_MODEL:-anthropic/claude-sonnet-4-5}",
+  "model": "${OPENCODE_MODEL:-anthropic/claude-sonnet-4-6}",
   "share": "disabled",
   "autoupdate": false
 }
@@ -32,7 +32,7 @@ EOF
       cat > "$CONFIG_FILE" <<EOF
 {
   "\$schema": "https://opencode.ai/config.json",
-  "model": "${OPENCODE_MODEL:-openai/gpt-4o}",
+  "model": "${OPENCODE_MODEL:-openai/gpt-5.4}",
   "share": "disabled",
   "autoupdate": false
 }
@@ -42,7 +42,7 @@ EOF
       cat > "$CONFIG_FILE" <<EOF
 {
   "\$schema": "https://opencode.ai/config.json",
-  "model": "${OPENCODE_MODEL:-amazon-bedrock/anthropic.claude-sonnet-4-5-v1}",
+  "model": "${OPENCODE_MODEL:-amazon-bedrock/global.anthropic.claude-sonnet-4-5-20250929-v1:0}",
   "share": "disabled",
   "autoupdate": false,
   "provider": {
@@ -60,7 +60,7 @@ EOF
       cat > "$CONFIG_FILE" <<EOF
 {
   "\$schema": "https://opencode.ai/config.json",
-  "model": "${OPENCODE_MODEL:-anthropic/claude-sonnet-4-5}",
+  "model": "${OPENCODE_MODEL:-anthropic/claude-sonnet-4-6}",
   "share": "disabled",
   "autoupdate": false
 }