diff --git a/CHANGELOG.md b/CHANGELOG.md
index fa9e77e..5fc506b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,16 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 
+## [1.0.1] - 2026-06-19
+
+### Changed
+
+- Updated the quickstart to install from the exact `v1.0.1` release tag and documented
+  that the pin must move with future releases.
+- Changed force installs to replace the validated destination directory so stale files
+  cannot survive across versions.
+- Added a GitHub hardening checklist for repository-side enforcement alongside Trellis.
+
 ## [1.0.0] - 2026-06-19
 
 First stable release of `codebase-trellis`.
diff --git a/README.md b/README.md
index 11a0bf2..36219a1 100644
--- a/README.md
+++ b/README.md
@@ -23,13 +23,16 @@ It is not a Git command wrapper. The default behavior is inspection and planning
 
 ## Quickstart
 
-Clone this repository locally first, then run the install script from the repository root.
+Clone this repository locally, check out the exact release tag, then run the install
+script from the repository root.
 
 **Claude Code - PowerShell**
 
 ```powershell
 git clone https://github.com/Shaelz/codebase-trellis-skill.git
 cd codebase-trellis-skill
+git fetch --tags
+git checkout v1.0.1
 .\scripts\install-user.ps1
 ```
 
@@ -38,11 +41,17 @@ cd codebase-trellis-skill
 ```bash
 git clone https://github.com/Shaelz/codebase-trellis-skill.git
 cd codebase-trellis-skill
+git fetch --tags
+git checkout v1.0.1
 bash scripts/install-user.sh
 ```
 
 Then restart Claude Code and type `/codebase-trellis` in any project.
 
+These commands intentionally pin release `v1.0.1`.
+The pinned tag must be updated here whenever a newer release is published.
+Advanced users may install from `main` only when intentionally testing unreleased changes.
+
 ## Install paths
 
 | Goal | Run from | Command |
@@ -54,7 +63,10 @@ Then restart Claude Code and type `/codebase-trellis` in any project.
 
 User-level install makes the skill available in all projects. Project-local install adds it only to the current project's `.claude/skills/` directory. For project-local installs, navigate to your project root first, then call the script using the full path to where you cloned this repo.
 
-If an installation already exists, the scripts exit with an error unless you pass `-Force` (PowerShell) or `--force` (bash).
+If an installation already exists, the scripts exit with an error unless you pass
+`-Force` (PowerShell) or `--force` (bash). Force mode removes the existing
+`codebase-trellis` skill directory after validating its exact expected path, then copies
+the selected version. This prevents stale files from surviving an upgrade.
 
 ## Usage
 
@@ -90,6 +102,9 @@ Trellis operates within four safety layers:
 
 These layers are not equivalent. A skill rule does not substitute for a protected branch. A local grep does not substitute for GitHub secret scanning.
 
+For a practical enforcement checklist, see
+[GitHub hardening for Trellis](docs/github-hardening.md).
+
 ## What Trellis never does without explicit approval
 
 - `git add .`
diff --git a/docs/github-hardening.md b/docs/github-hardening.md
new file mode 100644
index 0000000..1404862
--- /dev/null
+++ b/docs/github-hardening.md
@@ -0,0 +1,28 @@
+# GitHub hardening for Trellis
+
+Trellis provides behavioral guidance, inspection, and approval gates for AI-assisted
+Git work. GitHub branch protections and rulesets provide repository-side enforcement.
+Use both when changes to protected branches must be controlled regardless of which
+developer, agent, or local tool performs the Git operation.
+
+Availability varies by repository visibility, GitHub plan, and organization settings.
+Use the controls available to your repository and verify the resulting rules directly.
+
+## Practical checklist
+
+- Protect `main` with a branch protection rule or ruleset.
+- Require pull requests before changes can merge into `main`.
+- Require the existing `verify` workflow status check before merge.
+- Block force pushes to protected branches.
+- Block protected branch deletion where appropriate.
+- Enable secret scanning and push protection where available.
+- Keep GitHub Actions permissions least-privilege and read-only by default. Grant write
+  access only to workflows that require it.
+- Protect release tags such as `v*` from deletion or retagging where available.
+
+Local Git hooks and Claude Code hooks can add useful checks earlier in the workflow.
+They are optional companion layers, not substitutes for GitHub protections, because
+local controls can be absent, bypassed, or configured differently on another machine.
+
+After configuring protections, test them with a pull request and confirm that GitHub
+blocks merge until the required `verify` check passes.
diff --git a/scripts/install-project.ps1 b/scripts/install-project.ps1
index df78031..b76dc59 100644
--- a/scripts/install-project.ps1
+++ b/scripts/install-project.ps1
@@ -6,8 +6,9 @@
     Run this from the root of the project where you want to install the skill.
 
 .PARAMETER Force
-    Overwrite an existing installation. Without this flag the script exits if the
-    destination already exists.
+    Replace an existing installation. Without this flag the script exits if the
+    destination already exists. Replacement removes the validated skill directory
+    before copying so stale files cannot survive.
 
 .EXAMPLE
     .\path\to\install-project.ps1
@@ -23,7 +24,9 @@ $ErrorActionPreference = 'Stop'
 
 $scriptDir  = Split-Path -Parent $MyInvocation.MyCommand.Path
 $sourceDir  = Join-Path $scriptDir '..\skills\codebase-trellis'
-$destDir    = Join-Path (Get-Location) '.claude\skills\codebase-trellis'
+$projectRoot    = [System.IO.Path]::GetFullPath((Get-Location).Path)
+$expectedParent = [System.IO.Path]::GetFullPath((Join-Path $projectRoot '.claude\skills'))
+$destDir        = [System.IO.Path]::GetFullPath((Join-Path $expectedParent 'codebase-trellis'))
 
 $sourceDir = (Resolve-Path $sourceDir).Path
 
@@ -35,7 +38,17 @@ if (Test-Path $destDir) {
         Write-Error "Destination already exists: $destDir`nRe-run with -Force to overwrite."
         exit 1
     }
-    Write-Host "[-Force] Overwriting existing installation."
+    $hasExpectedParent = [System.StringComparer]::OrdinalIgnoreCase.Equals(
+        [System.IO.Path]::GetDirectoryName($destDir),
+        $expectedParent
+    )
+    $hasExpectedLeaf = [System.IO.Path]::GetFileName($destDir) -eq 'codebase-trellis'
+    if (-not $hasExpectedParent -or -not $hasExpectedLeaf) {
+        Write-Error "Refusing to remove unexpected destination: $destDir"
+        exit 1
+    }
+    Write-Host "[-Force] Removing existing installation."
+    Remove-Item -LiteralPath $destDir -Recurse -Force
 }
 
 if (-not (Test-Path $destDir)) {
diff --git a/scripts/install-project.sh b/scripts/install-project.sh
index ddb4f5d..3b6f847 100644
--- a/scripts/install-project.sh
+++ b/scripts/install-project.sh
@@ -11,7 +11,9 @@ set -euo pipefail
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 SOURCE_DIR="$(cd "$SCRIPT_DIR/../skills/codebase-trellis" && pwd)"
-DEST_DIR="$(pwd)/.claude/skills/codebase-trellis"
+PROJECT_ROOT="$(pwd)"
+EXPECTED_PARENT_DIR="$PROJECT_ROOT/.claude/skills"
+DEST_DIR="$EXPECTED_PARENT_DIR/codebase-trellis"
 
 FORCE=false
 for arg in "$@"; do
@@ -24,13 +26,18 @@ done
 echo "Source : $SOURCE_DIR"
 echo "Dest   : $DEST_DIR"
 
-if [ -d "$DEST_DIR" ]; then
+if [ -e "$DEST_DIR" ] || [ -L "$DEST_DIR" ]; then
     if [ "$FORCE" = false ]; then
         echo "Error: destination already exists: $DEST_DIR" >&2
         echo "Re-run with --force to overwrite." >&2
         exit 1
     fi
-    echo "[--force] Overwriting existing installation."
+    if [ "$(dirname "$DEST_DIR")" != "$EXPECTED_PARENT_DIR" ] || [ "$(basename "$DEST_DIR")" != "codebase-trellis" ]; then
+        echo "Error: refusing to remove unexpected destination: $DEST_DIR" >&2
+        exit 1
+    fi
+    echo "[--force] Removing existing installation."
+    rm -rf -- "$DEST_DIR"
 fi
 
 mkdir -p "$DEST_DIR"
diff --git a/scripts/install-user.ps1 b/scripts/install-user.ps1
index 8463199..3bf9941 100644
--- a/scripts/install-user.ps1
+++ b/scripts/install-user.ps1
@@ -4,8 +4,9 @@
     Installs the codebase-trellis skill to the user-level Claude Code skills directory.
 
 .PARAMETER Force
-    Overwrite an existing installation. Without this flag the script exits if the
-    destination already exists.
+    Replace an existing installation. Without this flag the script exits if the
+    destination already exists. Replacement removes the validated skill directory
+    before copying so stale files cannot survive.
 
 .EXAMPLE
     .\scripts\install-user.ps1
@@ -21,7 +22,8 @@ $ErrorActionPreference = 'Stop'
 
 $scriptDir  = Split-Path -Parent $MyInvocation.MyCommand.Path
 $sourceDir  = Join-Path $scriptDir '..\skills\codebase-trellis'
-$destDir    = Join-Path $HOME '.claude\skills\codebase-trellis'
+$expectedParent = [System.IO.Path]::GetFullPath((Join-Path $HOME '.claude\skills'))
+$destDir        = [System.IO.Path]::GetFullPath((Join-Path $expectedParent 'codebase-trellis'))
 
 $sourceDir = (Resolve-Path $sourceDir).Path
 
@@ -33,7 +35,17 @@ if (Test-Path $destDir) {
         Write-Error "Destination already exists: $destDir`nRe-run with -Force to overwrite."
         exit 1
     }
-    Write-Host "[-Force] Overwriting existing installation."
+    $hasExpectedParent = [System.StringComparer]::OrdinalIgnoreCase.Equals(
+        [System.IO.Path]::GetDirectoryName($destDir),
+        $expectedParent
+    )
+    $hasExpectedLeaf = [System.IO.Path]::GetFileName($destDir) -eq 'codebase-trellis'
+    if (-not $hasExpectedParent -or -not $hasExpectedLeaf) {
+        Write-Error "Refusing to remove unexpected destination: $destDir"
+        exit 1
+    }
+    Write-Host "[-Force] Removing existing installation."
+    Remove-Item -LiteralPath $destDir -Recurse -Force
 }
 
 if (-not (Test-Path $destDir)) {
diff --git a/scripts/install-user.sh b/scripts/install-user.sh
index 770e4c0..1e940e8 100644
--- a/scripts/install-user.sh
+++ b/scripts/install-user.sh
@@ -9,7 +9,8 @@ set -euo pipefail
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 SOURCE_DIR="$(cd "$SCRIPT_DIR/../skills/codebase-trellis" && pwd)"
-DEST_DIR="$HOME/.claude/skills/codebase-trellis"
+EXPECTED_PARENT_DIR="$HOME/.claude/skills"
+DEST_DIR="$EXPECTED_PARENT_DIR/codebase-trellis"
 
 FORCE=false
 for arg in "$@"; do
@@ -22,13 +23,18 @@ done
 echo "Source : $SOURCE_DIR"
 echo "Dest   : $DEST_DIR"
 
-if [ -d "$DEST_DIR" ]; then
+if [ -e "$DEST_DIR" ] || [ -L "$DEST_DIR" ]; then
     if [ "$FORCE" = false ]; then
         echo "Error: destination already exists: $DEST_DIR" >&2
         echo "Re-run with --force to overwrite." >&2
         exit 1
     fi
-    echo "[--force] Overwriting existing installation."
+    if [ "$(dirname "$DEST_DIR")" != "$EXPECTED_PARENT_DIR" ] || [ "$(basename "$DEST_DIR")" != "codebase-trellis" ]; then
+        echo "Error: refusing to remove unexpected destination: $DEST_DIR" >&2
+        exit 1
+    fi
+    echo "[--force] Removing existing installation."
+    rm -rf -- "$DEST_DIR"
 fi
 
 mkdir -p "$DEST_DIR"
diff --git a/scripts/verify-skill-package.ps1 b/scripts/verify-skill-package.ps1
index 8c5a810..5853e9a 100644
--- a/scripts/verify-skill-package.ps1
+++ b/scripts/verify-skill-package.ps1
@@ -44,6 +44,7 @@ Check-File "scripts\check-ascii-punctuation.ps1"
 Check-File "docs\FUTURE_BRANCHES.md"
 Check-File "docs\V1_RELEASE_PLAN.md"
 Check-File "docs\design-decisions.md"
+Check-File "docs\github-hardening.md"
 Check-File "docs\source-review.md"
 Check-File ".gitignore"
 Check-File "README.md"
diff --git a/scripts/verify-skill-package.sh b/scripts/verify-skill-package.sh
index 050ea43..61cc38f 100644
--- a/scripts/verify-skill-package.sh
+++ b/scripts/verify-skill-package.sh
@@ -39,6 +39,7 @@ check_file "scripts/check-ascii-punctuation.ps1"
 check_file "docs/FUTURE_BRANCHES.md"
 check_file "docs/V1_RELEASE_PLAN.md"
 check_file "docs/design-decisions.md"
+check_file "docs/github-hardening.md"
 check_file "docs/source-review.md"
 check_file ".gitignore"
 check_file "README.md"