[Feature] Detect and surface cascading errors across agents

[gnekt]

Problem

Suggested by u/Creative-Signal6813 on Reddit.

With 10 agents (currently) in a pipeline, accuracy compounds negatively. If each agent is 90% accurate independently, a 10-step chain drops to ~35% overall reliability. Concretely: if the Sorter misclassifies a note (files a project note into Resources), the Connector builds links on that wrong location, the Librarian reports healthy metrics on a broken structure, and the error propagates silently. There is no mechanism to catch or surface these cascading failures.

Proposed Solution

Add confidence signals and validation checkpoints:

1. Confidence tagging: agents tag their output with a confidence level (high/medium/low) in note frontmatter. Downstream agents that receive low-confidence input flag it for user review instead of building on it blindly.
2. Action log: a simple ``Meta/agent-log.md``` where each agent records what it did, why, and with what confidence. Makes silent failures visible and auditable.
3. Classification audit: add a phase to the Librarian's weekly review that samples recently filed notes and checks whether they're in the right place (cross-referencing content against folder location).
4. Rollback markers: when an agent modifies a note, it records the previous state so changes can be reverted if downstream validation fails.

Scope

Specific agent (specify below)

Agent (if applicable)

librarian, sorter, connector (all agents affected, but these three are the primary implementation points)

Alternatives Considered

No response

Additional Context

No response