fix(opencode): the 2.x home placeholder is not typed input, cut example included (Issue #60, Linux item 1)

An adapter can now name its placeholder as a pattern the box's first line
matches in full (input_placeholder_pattern); input_placeholder stays the
literal lib.sh greps for. opencode: `Ask anything… "<example>"`, the closing
quote optional because a box under ~65 columns cuts the example. Fixtures:
the 140-column herdr capture and a 60-column one with the cut example.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.agents/skills/lib_py/agents/adapters/opencode.py

@@ -50,6 +50,12 @@ class OpenCodeAgentAdapter(BaseAgentAdapter):
     def input_placeholder(self) -> Optional[str]:
         return ''
 
+    @property
+    def input_placeholder_pattern(self) -> Optional[str]:
+        # 2.x home screen: `Ask anything… "<example>"`, the example picked per
+        # launch and cut without its closing quote in a narrow box (Issue #60).
+        return r'Ask anything(?:…|\.\.\.)(?: "[^"]*"?)?'
+
     @property
     def input_rule_pattern(self) -> Optional[str]:
         # Kept for lib.sh's readiness corroboration; the input box itself is a