918f2f5652
Stage agents were spending most of their turn budget re-discovering files already known from prior stages/attempts. Root cause: nothing durable carries acquired knowledge across handoffs and retries. First four slices of the fix: - core:sourcedesc — new dependency-free module: describe(path, bytes) derives comment-free structural navigation metadata (module, bounded symbols, bounded imports, versioned format). Deliberately non-prose: descriptors are derived from agent-writable files and rendered into successor-stage context, so comments/docstrings/literals are excluded to close a prompt-injection channel. CAS post-image hash stays authoritative; descriptor is disposable navigation. - kernel retry-repair state (ContextFeedback): on retry, name the authoritative CAS images of files this stage already wrote so the agent patches them instead of re-reading to rediscover them. - kernel file-written manifest (SessionOrchestratorArtifacts): each produced file surfaced with its authoritative CAS image plus a comment-free structural descriptor (via core:sourcedesc, over recorded CAS bytes — replay-safe). - apps/server RepoMapIndexer: route the injected repo-map descriptor through the comment-free describe(). Previously scraped leading comments, which were embedded into L3 and surfaced verbatim to successor stages — an injection channel from one stage into the next. Structural facts (module + imports + symbols) remain as the retrieval signal. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>