Bug: Claude Code skips mandatory session-start files to optimize for speed over correctness

What happened

During a session with Claude Code (Opus 4.6), the user's project has mandatory session-start files that must be read before any work begins. These are documented in multiple places:

• CLAUDE.md (project rules, checked into the repo)
• plans/claude_vorgaben.md (authoritative rule source)
• MEMORY.md (auto-memory, persists across conversations)

The mandatory files include: claude_vorgaben.md, claude_fails.md, quality_gate.md, mq/session_queue.md, mq/session_status.md, and several others.

What Claude did: Instead of reading these files first, Claude immediately jumped into researching the user's bug reports (running Grep/Read on game code files). The user had to interrupt and explicitly say "als erstes: du liest dich ein" (first: read up on everything).

Additionally: When Claude did start reading mq/session_queue.md, the file was large and the Read tool returned a preview. Instead of reading the remaining parts, Claude noted "war zu groß, nur Preview gesehen" (was too large, only saw preview) and moved on — treating a mandatory file as optional because reading it fully was inconvenient.

Why this is problematic

1. Prioritizing speed over correctness: Claude's documented core problem (in the project's claude_fails.md line 1102) is: "Ich optimiere auf 'schnell fertig' statt auf 'richtig gemacht'" (I optimize for 'quickly done' instead of 'properly done'). This is exactly that pattern — skipping mandatory setup to get to the "real work" faster.

1. Repeat offense: This is a repetition of documented Fail #5 in the project's fail log: "Vorgaben ignoriert: Ohne claude_vorgaben.md und quality_gate.md zu lesen losgearbeitet" (Started working without reading the mandatory rule files).

1. Lazy truncation of mandatory reading: Declaring a mandatory file "too large" and only reading a preview is not acceptable. The file exists because it contains critical cross-machine session communication. Skipping parts of it means missing context that could affect the work.

Expected behavior

1. At session start, Claude should read ALL mandatory files BEFORE doing any other work — no exceptions, no shortcuts
2. If a file is too large for a single Read call, Claude should immediately read the remaining parts
3. "Too large" is never a valid reason to skip mandatory content — it's a reason to make multiple Read calls

Environment

• Claude Code CLI
• Model: claude-opus-4-6
• Platform: Windows 11
• The mandatory file list is defined in plans/claude_vorgaben.md and MEMORY.md