feat: Tiered agent memory — hot/cold/wiki layers for context management

[tamirdresher]

Problem

Agent history.md files grow to 70KB+ (18K tokens). Agents load everything at spawn, burning context window on old noise. Current summarization (>12KB threshold) helps but doesn't distinguish between recent actionable context and archived knowledge.

Proposal

Three-tier memory architecture:

Layer	File	Loaded	Content
Hot	history.md	Always at spawn	Core Context + last ~20 entries + active-issue-tagged entries
Cold	history-archive.md	On demand	Summarized old entries, preserved for reference
Durable	GitHub Wiki	Searchable by all agents	Major findings, architecture patterns, test results

Scribe maintains the split: During regular maintenance, move old unstructured work reports to archive first (biggest bloat source). Keep issue-tagged entries in hot layer until issue closes.

Spawn template change: Agents read hot by default. Only read cold when task explicitly references historical context.

Measurements

• Top agents: 34-74KB history files (8.8K-18.5K tokens)
• 82-96% is old learnings/work reports
• Realistic savings: 20-55% token reduction per spawn
• Wiki provides cross-agent knowledge sharing without loading into each agent's context

Deliverables

• Skill template: .squad/skills/tiered-history/SKILL.md
• Scribe charter update: hot/cold maintenance rules
• Wiki-write skill for durable knowledge
• Spawn template: conditional cold-layer loading

[tamirdresher]

Revision after checking main: The 12KB summarization threshold and history-archive.md pattern already exist. What's NEW in this proposal: (1) explicit hot/cold tier model with promotion/demotion logic (not just 'summarize at 12KB'), (2) wiki as a third durable layer for cross-agent knowledge sharing, (3) issue-tag-based retention (keep entries tagged with active issues in hot layer). The runtime tiered retrieval is the gap.

[github-actions]

📋 Assigned to Procedures (Prompt Engineer)

Issue: #600 — feat: Tiered agent memory — hot/cold/wiki layers for context management

Procedures will pick this up in the next Copilot session.

For Copilot coding agent: If enabled, this issue will be worked automatically.
Otherwise, start a Copilot session and say:
Procedures, work on issue #600

[github-actions]

🏗️ Squad Triage — Flight (Lead)

Issue: #600 — feat: Tiered agent memory — hot/cold/wiki layers for context management
Assigned to: FIDO (Quality Owner)
Reason: Issue relates to testing/quality work

@copilot evaluation: 🔴 Not suitable — issue involves work outside the coding agent's capability profile.

Team roster:

• Flight (Lead) → label: squad:flight
• Procedures (Prompt Engineer) → label: squad:procedures
• EECOM (Core Dev) → label: squad:eecom
• FIDO (Quality Owner) → label: squad:fido
• PAO (DevRel) → label: squad:pao
• CAPCOM (SDK Expert) → label: squad:capcom
• CONTROL (TypeScript Engineer) → label: squad:control
• Surgeon (Release Manager) → label: squad:surgeon
• Booster (CI/CD Engineer) → label: squad:booster
• GNC (Node.js Runtime) → label: squad:gnc
• Network (Distribution) → label: squad:network
• RETRO (Security) → label: squad:retro
• INCO (CLI UX & Visual Design) → label: squad:inco
• GUIDO (VS Code Extension) → label: squad:guido
• Telemetry (Aspire & Observability) → label: squad:telemetry
• VOX (REPL & Interactive Shell) → label: squad:vox
• DSKY (TUI Engineer) → label: squad:dsky
• Sims (E2E Test Engineer) → label: squad:sims
• Handbook (SDK Usability) → label: squad:handbook
• Ralph (Work Monitor) → label: squad:ralph
• @copilot (Coding Agent) → label: squad:copilot

To reassign, remove the current squad:* label and add the correct one.

[bradygaster]

Triage: Contributor-submitted feature (Tamir). Tiered memory architecture for agent context management. Assigned to Procedures (prompt architecture) for review.

[diberry]

🔄 Ralph status: Feature — 3-tier memory (hot/cold/wiki). Research done in #686. Superset of #595. No implementation PR yet.