fix: enable memory writes for non-implementation agents

.config/opencode/.memory/knowledge.md

@@ -0,0 +1,39 @@
+## Project Overview
+
+This is the OpenCode agentic configuration for a multi-agent coding workflow. It defines agent roles, permissions, quality pipelines, and project memory conventions used across all projects that load this config.
+
+- **Config root:** `~/.config/opencode/`
+- **Config file:** `opencode.jsonc` — defines default agent, plugins, global permissions, and MCP servers.
+- **Agent definitions:** `agents/*.md` — one file per agent with YAML frontmatter (model, permissions, temperature) and markdown instructions.
+- **Memory system:** `.memory/` — persistent project knowledge, decisions, plans, and research in markdown.
+- **Cross-tool instruction files:** `AGENTS.md`, `CLAUDE.md`, `.github/copilot-instructions.md`, `.cursorrules` — derived views of project knowledge for different agentic tools.
+
+## Agent Architecture
+
+10 agents with distinct roles, models, and permission profiles. See [Agent Roster in AGENTS.md](../AGENTS.md#agent-roster) for the full table.
+
+### Permission Model
+
+- **Full edit access:** `lead`, `coder`, `librarian`.
+- **Memory-only edit access:** `reviewer`, `tester`, `explorer`, `researcher`, `critic`, `sme`, `designer` — these agents have `permission.edit: allow` but are instructed to keep code/source edits read-only. Their edit permission exists solely to support `.memory/*` writes for recording duties (verdicts, discoveries, research, guidance, design decisions).
+- **No edit access:** none (all agents can write `.memory/*`).
+
+See [Decision: Agent Memory Write Access](decisions.md#agent-memory-write-access) for rationale and guardrails.
+
+### Memory Write Guardrails
+
+Agents with memory-only edit access are constrained by instruction-level guardrails (not path-scoped config, which OpenCode does not support):
+
+1. Each agent's instructions explicitly state: "`.memory/*` writes are allowed for [specific duty]; code/source edits remain read-only."
+2. Each agent's instructions list tool restrictions (e.g., "Disallowed: non-memory file edits").
+3. The `permission.edit: allow` fallback is necessary because OpenCode's `permission.edit` does not support path-scoped allow/deny syntax.
+
+## Quality Pipeline
+
+Tiered pipeline (Tier 1/2/3) defined in `agents/lead.md`. Standard flow: `explorer/researcher → coder → reviewer → tester → librarian`.
+
+## MCP Servers
+
+- **Context7:** Remote documentation lookup (`https://mcp.context7.com/mcp`)
+- **GitHub Grep:** Remote code search across public repos (`https://mcp.grep.app`)
+- **Playwright:** Local headless Chromium for UI testing