diff --git a/CLAUDE.md b/CLAUDE.md
index 7e598a7..9f43a23 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -78,7 +78,15 @@ This project uses speckit for feature specification and planning. Available comm
 
 Templates are stored in `.specify/templates/` and project constitution in `.specify/memory/constitution.md`.
 
-**Important:** After implementing a spec, always update `README.md` to reflect the new functionality.
+## Post-Implementation Checklist
+
+After completing any feature implementation or significant work:
+
+1. **Update README.md** - Ensure all new commands, options, and functionality are documented
+2. **Update spec status** - Mark the spec as "Implemented" in the spec.md file
+3. **Verify examples** - Ensure README examples still work with any changes
+
+This checklist ensures documentation stays in sync with the codebase.
 
 ## Active Technologies
 - Go 1.21+ (per IC-001) + Standard library only (os/exec for tmux, encoding/json for JSONL) (001-agent-mail-structure)
diff --git a/README.md b/README.md
index 31a0743..d219286 100644
--- a/README.md
+++ b/README.md
@@ -228,16 +228,21 @@ agentmail status offline
 
 ### mailman
 
-Start the mailman daemon to monitor mailboxes and notify agents.
+Start or stop the mailman daemon to monitor mailboxes and notify agents.
 
 ```bash
 agentmail mailman [--daemon]
+agentmail mailman stop
 ```
 
 **Flags:**
 
 - `--daemon` - Run in background (daemonize)
 
+**Subcommands:**
+
+- `stop` - Stop the running daemon gracefully
+
 **Behavior:**
 
 - Uses file watching (fsnotify) for instant notification on mailbox changes
@@ -245,7 +250,7 @@ agentmail mailman [--daemon]
 - Sends notifications to agents with `ready` status that have unread mail
 - Notifications sent via tmux: `tmux send-keys -t <window> "Check your agentmail"`
 - Stores PID in `.agentmail/mailman.pid`
-- Gracefully shuts down on SIGTERM/SIGINT
+- Gracefully shuts down on SIGTERM/SIGINT or when `stop` command is issued
 
 **Examples:**
 
@@ -255,14 +260,22 @@ agentmail mailman
 
 # Run as background daemon
 agentmail mailman --daemon
+
+# Stop the running daemon
+agentmail mailman stop
 ```
 
-**Exit codes:**
+**Exit codes (start):**
 
-- `0` - Daemon started/stopped successfully
+- `0` - Daemon started successfully
 - `1` - Error (failed to start, PID file error, etc.)
 - `2` - Daemon already running
 
+**Exit codes (stop):**
+
+- `0` - Stop signal sent successfully
+- `1` - Error (stop already pending or filesystem error)
+
 ### onboard
 
 Output AI-optimized onboarding context about AgentMail.
diff --git a/internal/cli/mailman_stop.go b/internal/cli/mailman_stop.go
index f6d9880..86181da 100644
--- a/internal/cli/mailman_stop.go
+++ b/internal/cli/mailman_stop.go
@@ -17,6 +17,10 @@ type MailmanStopOptions struct {
 // MailmanStop implements the agentmail mailman stop command.
 // Creates a .stop file to signal the daemon to shut down.
 //
+// The function attempts to find the repository root via FindGitRoot,
+// falling back to os.Getwd if not in a git repository. If both fail,
+// repoRoot will be empty and file creation will fail with a clear error.
+//
 // Exit codes:
 // - 0: Success (stop signal sent)
 // - 1: Error (file exists or filesystem error)
diff --git a/internal/cli/mailman_stop_test.go b/internal/cli/mailman_stop_test.go
index 6df4d6a..60cb096 100644
--- a/internal/cli/mailman_stop_test.go
+++ b/internal/cli/mailman_stop_test.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
 
 	"agentmail/internal/daemon"
@@ -157,7 +158,7 @@ func TestMailmanStop_FilesystemError_ReturnsError(t *testing.T) {
 
 	// Verify error message contains expected prefix
 	expectedPrefix := "Failed to send stop signal:"
-	if len(stderr.String()) < len(expectedPrefix) || stderr.String()[:len(expectedPrefix)] != expectedPrefix {
+	if !strings.HasPrefix(stderr.String(), expectedPrefix) {
 		t.Errorf("Expected stderr to start with %q, got %q", expectedPrefix, stderr.String())
 	}
 
diff --git a/specs/012-mailman-stop/contracts/cli.md b/specs/012-mailman-stop/contracts/cli.md
index d76f281..91ff770 100644
--- a/specs/012-mailman-stop/contracts/cli.md
+++ b/specs/012-mailman-stop/contracts/cli.md
@@ -54,12 +54,14 @@ Failed to send stop signal: <error message>
 ### Fire-and-Forget Pattern
 
 The stop command creates a signal file and immediately exits with code 0. It does NOT:
+
 - Wait for the daemon to terminate
 - Verify the daemon is running
 - Verify the daemon received the signal
 - Delete any files
 
 The daemon is responsible for:
+
 - Detecting the `.stop` file via file watcher
 - Removing the `.stop` file
 - Removing the `.pid` file
@@ -76,6 +78,7 @@ The stop mechanism uses file creation as inter-process communication:
 5. Daemon initiates shutdown and cleans up files
 
 This approach:
+
 - Requires no process validation
 - Works cross-platform
 - Uses existing file watcher infrastructure
diff --git a/specs/012-mailman-stop/data-model.md b/specs/012-mailman-stop/data-model.md
index 14c44d4..4cf35e6 100644
--- a/specs/012-mailman-stop/data-model.md
+++ b/specs/012-mailman-stop/data-model.md
@@ -19,6 +19,7 @@ This feature introduces a file-based signaling mechanism for stopping the daemon
 **Purpose**: Acts as an inter-process communication (IPC) mechanism between the CLI stop command and the running daemon.
 
 **Operations**:
+
 | Operation | Actor | Trigger |
 |-----------|-------|---------|
 | Create | CLI (stop command) | User runs `agentmail mailman stop` |
diff --git a/specs/012-mailman-stop/plan.md b/specs/012-mailman-stop/plan.md
index 9e9b510..52751fd 100644
--- a/specs/012-mailman-stop/plan.md
+++ b/specs/012-mailman-stop/plan.md
@@ -31,6 +31,7 @@ Add `agentmail mailman stop` subcommand to gracefully terminate the mailman daem
 | IV. Standard Library | ✅ PASS | Uses only stdlib (os package for file operations) |
 
 **Quality Gates Required**:
+
 1. `gofmt -l .` - no output
 2. `go mod verify` - pass
 3. `go vet ./...` - pass
diff --git a/specs/012-mailman-stop/quickstart.md b/specs/012-mailman-stop/quickstart.md
index 5de6109..29917bf 100644
--- a/specs/012-mailman-stop/quickstart.md
+++ b/specs/012-mailman-stop/quickstart.md
@@ -135,11 +135,13 @@ mailmanCmd := &ffcli.Command{
 ### Step 6: Write Tests
 
 #### internal/cli/mailman_stop_test.go
+
 - Test success case (file created)
 - Test "stop already pending" (file exists)
 - Test filesystem error (permissions)
 
 #### internal/daemon/watcher_test.go (extend existing)
+
 - Test stop file detection triggers shutdown
 
 ## Key Files to Modify
diff --git a/specs/012-mailman-stop/research.md b/specs/012-mailman-stop/research.md
index ecf2b1b..078dfbc 100644
--- a/specs/012-mailman-stop/research.md
+++ b/specs/012-mailman-stop/research.md
@@ -12,6 +12,7 @@
 **Decision**: Create an empty `.stop` file in `.agentmail/` directory. Daemon detects via existing fsnotify watcher.
 
 **Rationale**:
+
 - File creation is a simple, cross-platform IPC mechanism
 - The daemon already has fsnotify watching `.agentmail/` for mailbox changes
 - No need for Unix signals, process validation, or syscall dependencies
@@ -33,12 +34,14 @@
 **Decision**: Use `os.OpenFile` with `O_CREATE|O_EXCL` flags to atomically create the file only if it doesn't exist.
 
 **Rationale**:
+
 - `O_EXCL` flag causes the open to fail if file exists
 - This is atomic at the filesystem level
 - No race conditions between check and create
 - Go's `os.OpenFile` supports this directly
 
 **Implementation**:
+
 ```go
 // Atomic create - fails if file exists
 f, err := os.OpenFile(stopFilePath, os.O_CREATE|os.O_EXCL|os.O_WRONLY, 0600)
@@ -59,12 +62,14 @@ return "Stop signal sent"
 **Decision**: Extend the existing `FileWatcher` to detect CREATE events for `.stop` file in `.agentmail/` directory.
 
 **Rationale**:
+
 - The daemon already watches `.agentmail/` and `mailboxes/` directories
 - fsnotify provides CREATE events for new files
 - No additional polling or infrastructure needed
 - Detection is nearly instant (< 100ms typically)
 
 **Implementation Notes**:
+
 - The watcher's `Run()` function receives all events
 - Filter for `fsnotify.Create` events where filename is `.stop`
 - When detected, trigger graceful shutdown sequence
@@ -74,6 +79,7 @@ return "Stop signal sent"
 **Question**: What's the correct order for daemon shutdown?
 
 **Decision**: Follow this sequence:
+
 1. Detect `.stop` file
 2. Remove `.stop` file (acknowledge receipt)
 3. Close file watcher (stops notification loop)
@@ -82,11 +88,13 @@ return "Stop signal sent"
 6. Exit with code 0
 
 **Rationale**:
+
 - Removing `.stop` first prevents stale signal files
 - Closing watcher before PID removal ensures clean state
 - Matches existing signal-based shutdown sequence in `runForeground()`
 
 **Existing Code Reference** (`internal/daemon/daemon.go:249-271`):
+
 ```go
 // Wait for shutdown signal or test stop
 <-sigChan
diff --git a/specs/012-mailman-stop/spec.md b/specs/012-mailman-stop/spec.md
index eb9b4d2..9348951 100644
--- a/specs/012-mailman-stop/spec.md
+++ b/specs/012-mailman-stop/spec.md
@@ -53,7 +53,7 @@ An agent operator runs the stop command when a previous stop is already pending
 - **FR-001**: When `agentmail mailman stop` is invoked, the CLI shall attempt to create the file `.agentmail/.stop`.
 - **FR-002**: When the `.stop` file is created successfully, the CLI shall output "Stop signal sent" to stdout and exit with code 0.
 - **FR-003**: If the `.stop` file already exists, then the CLI shall output "Stop already pending" to stderr and exit with code 1.
-- **FR-004**: If the `.stop` file cannot be created due to a filesystem error, then the CLI shall output "Failed to send stop signal: <error>" to stderr and exit with code 1.
+- **FR-004**: If the `.stop` file cannot be created due to a filesystem error, then the CLI shall output "Failed to send stop signal: \<error\>" to stderr and exit with code 1.
 
 **Daemon Stop File Detection:**
 
diff --git a/specs/012-mailman-stop/tasks.md b/specs/012-mailman-stop/tasks.md
index aa31d67..ba7d1f3 100644
--- a/specs/012-mailman-stop/tasks.md
+++ b/specs/012-mailman-stop/tasks.md
@@ -16,6 +16,7 @@
 ## Path Conventions
 
 Based on plan.md structure (Go CLI project):
+
 - `cmd/agentmail/main.go` - CLI entry point
 - `internal/daemon/` - Daemon package (existing + modifications)
 - `internal/cli/` - CLI handlers (existing + new)
@@ -75,7 +76,7 @@ Based on plan.md structure (Go CLI project):
 ### Implementation for User Story 2
 
 - [x] T017 [US2] Add os.IsExist error handling for "Stop already pending" message in internal/cli/mailman_stop.go
-- [x] T018 [US2] Add generic filesystem error handling "Failed to send stop signal: <error>" in internal/cli/mailman_stop.go
+- [x] T018 [US2] Add generic filesystem error handling "Failed to send stop signal: \<error\>" in internal/cli/mailman_stop.go
 - [x] T019 [US2] Run tests to verify US2: `go test -v ./internal/cli/... -run MailmanStop`
 
 **Checkpoint**: Both user stories complete - full stop functionality with error handling
@@ -103,7 +104,7 @@ Based on plan.md structure (Go CLI project):
 
 ### Phase Dependencies
 
-```
+```text
 Phase 1 (Setup)           → No dependencies
 Phase 2 (US1)             → Depends on Phase 1
 Phase 3 (US2)             → Depends on Phase 2 (shares MailmanStop function)