feat: add Safe Exit protocol for blocked tasks under new task file convention

Agents no longer commit task files, so when an agent safe-exits:
- Agent notifies coordinator with detailed blocking message (what happened, what was tried, suggested fix)
- Agent commits any partial source code progress and pushes
- Coordinator updates task file on main with status: blocked and the reason
- Coordinator attempts resolution, spawns new agent if resolved

Also removed stale 'task file conflicts' from merge workflow since
agents no longer commit task files.

.opencode/agents/coordinator.md

@@ -70,11 +70,10 @@ This is the most critical coordinator responsibility. Follow it exactly:
    git merge feat/<task-name> --no-edit
    ```
 
-   If merge conflicts occur:
-   - **Source code conflicts between parallel tasks** that modify the same file: Resolve them yourself. Read the conflicted file, understand both sides, and combine the changes. Both sets of changes are valid — they were just developed in parallel.
-   - **Task file conflicts** (`tasks/*.md`): These happen when multiple agents commit task files. Remove the conflicting task files before merging (`rm -rf tasks/`), merge, then restore from backup. Or use `git checkout --theirs tasks/` to accept the incoming versions.
-   - **Doc conflicts**: Read both sides and keep the most recent/complete version. Often one branch cleaned up drift tables while another updated status.
-   - **If truly unresolvable**: Message the original agent's session for guidance, or ask the user.
+    If merge conflicts occur:
+    - **Source code conflicts between parallel tasks** that modify the same file: Resolve them yourself. Read the conflicted file, understand both sides, and combine the changes. Both sets of changes are valid — they were just developed in parallel.
+    - **Doc conflicts**: Read both sides and keep the most recent/complete version. Often one branch cleaned up drift tables while another updated status.
+    - **If truly unresolvable**: Message the original agent's session for guidance, or ask the user.
 
 3. **Validate after every merge:**
    ```bash
@@ -110,6 +109,38 @@ When multiple tasks complete around the same time, merge them **one at a time**
 
 If two tasks modify the same source files and were developed in parallel, you WILL get merge conflicts. This is expected — resolve them.
 
+### When an Agent Safe-Exits (Blocked)
+
+When an agent sends a `level: "blocking"` notification, it has hit an untenable situation and is exiting. This is the Safe Exit protocol — it's important, don't ignore it.
+
+1. **Read the blocking message carefully.** The agent should have included what it was trying to do, what went wrong, what it tried, and suggested resolution.
+
+2. **Get more context if needed:**
+   ```text
+   memory({tool: "messages", args: {sessionId: "ses_", role: "assistant"}})
+   ```
+   Read the agent's session to understand what actually happened.
+
+3. **Update the task file on main:**
+   ```bash
+   # Edit tasks/<task-id>.md
+   # status: blocked
+   # ## Notes
+   # Blocked: <reason from agent's message>
+   git add tasks/<task-id>.md
+   git commit -m "blocked(<task-id>): <reason>"
+   git push origin main
+   ```
+
+4. **Try to resolve the blocker:**
+   - Missing context? Send it via `worktree({action: "message", ...})` — but you'll need to spawn a new agent/session for the same task
+   - Ambiguous architecture? Ask the user to clarify
+   - Scope too large? Decompose into smaller tasks
+   - External dependency (tool bug, env issue)? Escalate to user
+
+5. **If you can resolve it:** Spawn a new agent for the same task with the additional context or adjusted scope.
+   **If you can't:** Move on to other independent work and flag the blocked task for later resolution.
+
 ## Spawning Agents
 
 ### Constructing the Spawn Prompt
@@ -238,18 +269,18 @@ When multiple agents commit task files in parallel branches, merging causes conf
 
 ### Coordinator Responsibilities
 
-After merging a task's source code changes into main, update the task file:
+After a task completes and is merged, update the task file on main:
 1. Find the task file in `tasks/`
-2. Update frontmatter `status: completed` (or `blocked` / `failed`)
+2. Update frontmatter `status: completed` (or `blocked` if the agent safe-exited)
 3. Add a brief summary to the `## Summary` section (from the agent's completion notification)
 4. Commit on main: `git commit -m "chore: update task <id> status to completed"`
+5. Push main
 
 ### If an Agent Accidentally Commits a Task File
 
-If `git merge` complains about conflicting task files:
-- Don't spend time resolving them — it's just metadata
-- Use `git checkout --theirs tasks/` to accept the incoming version, or temporarily remove `tasks/` before merging
-- After merge, update the task files on main with correct status
+If `git merge` complains about conflicting task files (this shouldn't happen with the new convention, but just in case):
+- Use `git checkout --theirs tasks/<file>.md` to accept the incoming version, or remove the local copy before merging
+- After merge, update the task file on main with the correct status
 
 ## Context Management
 

.opencode/agents/implementation-specialist.md

@@ -149,11 +149,17 @@ When task becomes untendable:
 ### Process
 
 1. **Stop** - don't force through
-2. **Notify coordinator**:
+2. **Notify coordinator** with a detailed blocking message. Include:
+   - What you were trying to do
+   - What went wrong (specific error, missing dep, ambiguous spec, etc.)
+   - What you've already tried
+   - What you think would resolve it (if you know)
    ```text
-   worktree({action: "notify", args: {message: "Blocked on <task-id>: <reason>", level: "blocking"}})
+   worktree({action: "notify", args: {message: "Blocked on <task-id>: <detailed explanation including what was attempted, what failed, and suggested resolution>", level: "blocking"}})
    ```
-3. **Exit** - coordinator handles escalation
+3. **Commit any partial source code progress** if it's coherent (you may not have any — that's fine)
+4. **Push your branch** so the coordinator can inspect your work if needed
+5. **Exit** - coordinator handles escalation
 
 ### Wrong Directory Recovery