fix(agents): pass contextFiles to createAgentSession for openai-completions API

Previously, `contextFiles` was resolved from workspace bootstrap files
(SOUL.md, USER.md, IDENTITY.md) and embedded into the system prompt via
`buildEmbeddedSystemPrompt`, but an empty array `[]` was passed to
`createAgentSession`. Some providers using the openai-completions API
may use the `contextFiles` parameter directly instead of relying solely
on the system prompt override.

This fix ensures bootstrap files are passed both:
1. Embedded in the system prompt (existing behavior)
2. Via the `contextFiles` parameter to `createAgentSession`

This addresses the issue where models using openai-completions API
(like Ollama) were not receiving workspace bootstrap file content.

Fixes #3775

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/agents/pi-embedded-runner/compact.ts

@@ -397,7 +397,7 @@ export async function compactEmbeddedPiSessionDirect(
         sessionManager,
         settingsManager,
         skills: [],
-        contextFiles: [],
+        contextFiles,
         additionalExtensionPaths,
       }));
 

src/agents/pi-embedded-runner/run/attempt.ts

@@ -460,7 +460,7 @@ export async function runEmbeddedAttempt(
         sessionManager,
         settingsManager,
         skills: [],
-        contextFiles: [],
+        contextFiles,
         additionalExtensionPaths,
       }));
       if (!session) {