diff --git a/.github/workflows/test-fish.yml b/.github/workflows/test-fish.yml
new file mode 100644
index 00000000..bfe000b0
--- /dev/null
+++ b/.github/workflows/test-fish.yml
@@ -0,0 +1,36 @@
+name: Fish tests
+
+on:
+  push:
+    paths:
+      - fish/**
+      - scripts/git_main_branch
+      - .github/workflows/test-fish.yml
+  pull_request:
+    paths:
+      - fish/**
+      - scripts/git_main_branch
+      - .github/workflows/test-fish.yml
+
+jobs:
+  git-wrapper:
+    name: Git wrapper (${{ matrix.os }})
+    strategy:
+      matrix:
+        os: [macos-latest, ubuntu-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v5
+
+      - name: Install Fish on macOS
+        if: runner.os == 'macOS'
+        run: brew install fish
+
+      - name: Install Fish on Linux
+        if: runner.os == 'Linux'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y fish
+
+      - name: Test Git wrapper
+        run: fish --no-config fish/tests/git_wrapper_test.fish
diff --git a/docs/adr/023-ci-lint-et-installation.md b/docs/adr/023-ci-lint-et-installation.md
index 25840750..46a4d2eb 100644
--- a/docs/adr/023-ci-lint-et-installation.md
+++ b/docs/adr/023-ci-lint-et-installation.md
@@ -13,11 +13,13 @@ au pire moment.
 
 ## Décision
 
-Deux workflows GitHub Actions. `lint.yml` vérifie la syntaxe Fish
+Trois workflows GitHub Actions. `lint.yml` vérifie la syntaxe Fish
 (`fish --no-execute`), le formatage (`fish_indent`), le Lua Neovim (`luacheck`)
-et les scripts shell (ShellCheck). `test.yml` exécute l'installation complète
-sur un runner macOS, apps payantes exclues (`SKIP_PAID_APPS`) et cibles Docker
-ignorées en l'absence de daemon (`DOCKER_OR_SKIP`).
+et les scripts shell (ShellCheck). `test-fish.yml` exécute les tests Fish sur
+macOS et Linux uniquement lorsque les fichiers qu'ils couvrent changent.
+`test.yml` exécute l'installation complète sur un runner macOS, apps payantes
+exclues (`SKIP_PAID_APPS`) et cibles Docker ignorées en l'absence de daemon
+(`DOCKER_OR_SKIP`).
 
 ## Conséquences
 
diff --git a/fish/conf.d/git-wrapper.fish b/fish/conf.d/git-wrapper.fish
new file mode 100644
index 00000000..159fb52d
--- /dev/null
+++ b/fish/conf.d/git-wrapper.fish
@@ -0,0 +1,151 @@
+set -l git_main_branch_script (path resolve (path dirname (status filename))/../../scripts/git_main_branch)
+
+function git --inherit-variable git_main_branch_script
+    set -l command_name
+    set -l command_arguments
+    set -l git_context
+    set -l git_prefix
+    set -l argument_index 1
+    while test $argument_index -le (count $argv)
+        set -l argument $argv[$argument_index]
+        switch "$argument"
+            case -C -c --git-dir --work-tree --namespace --config-env
+                if test $argument_index -eq (count $argv)
+                    break
+                end
+                set -l option_value $argv[(math $argument_index + 1)]
+                set -a git_context "$argument" "$option_value"
+                set -a git_prefix "$argument" "$option_value"
+                set argument_index (math $argument_index + 2)
+            case -p --paginate -P --no-pager --no-replace-objects --no-lazy-fetch --no-optional-locks --no-advice --bare
+                set -a git_prefix "$argument"
+                if contains -- "$argument" --no-replace-objects --no-lazy-fetch --no-optional-locks --bare
+                    set -a git_context "$argument"
+                end
+                set argument_index (math $argument_index + 1)
+            case '--git-dir=*' '--work-tree=*' '--namespace=*' '--config-env=*'
+                set -a git_context "$argument"
+                set -a git_prefix "$argument"
+                set argument_index (math $argument_index + 1)
+            case '-*'
+                break
+            case '*'
+                set command_name "$argument"
+                if test $argument_index -lt (count $argv)
+                    set command_arguments $argv[(math $argument_index + 1)..-1]
+                end
+                break
+        end
+    end
+
+    set -l tracked_tips
+    set -l sync_requested
+    if contains -- "$command_name" fetch pull; and not contains -- --dry-run $command_arguments
+        if not test -x "$git_main_branch_script"
+            echo "git: branch cleanup disabled: $git_main_branch_script is unavailable" >&2
+            command git $argv
+            return $status
+        end
+
+        set -l primary_branch (command "$git_main_branch_script" --strict $git_context)
+        if test $status -ne 0; or test -z "$primary_branch"
+            echo "git: branch cleanup disabled: primary branch lookup failed" >&2
+            command git $argv
+            return $status
+        end
+
+        set sync_requested 1
+        for branch_ref in (command git $git_context for-each-ref --format='%(refname)' refs/heads)
+            set -l branch (string replace refs/heads/ '' "$branch_ref")
+            if contains -- "$branch" "$primary_branch" development staging
+                continue
+            end
+
+            set -l upstream_ref (command git $git_context for-each-ref --format='%(upstream)' "$branch_ref")
+            if test -z "$upstream_ref"
+                continue
+            end
+
+            set -l upstream_oid (command git $git_context rev-parse --verify --quiet "$upstream_ref^{commit}")
+            if test $status -ne 0
+                echo "git: keeping $branch: upstream tip unavailable before $command_name" >&2
+                continue
+            end
+
+            set -a tracked_tips (string join \t -- "$branch" "$upstream_oid")
+        end
+    end
+
+    if test -n "$sync_requested"
+        command git $git_prefix $command_name --prune $command_arguments
+    else
+        command git $argv
+    end
+    set -l command_status $status
+
+    if test -n "$sync_requested"; and test $command_status -eq 0
+        for tracked_tip in $tracked_tips
+            set -l fields (string split \t -- "$tracked_tip")
+            set -l branch $fields[1]
+            set -l upstream_oid $fields[2]
+            set -l upstream_state (command git $git_context for-each-ref --format='%(upstream:track)' "refs/heads/$branch")
+            if test "$upstream_state" != '[gone]'
+                continue
+            end
+
+            set -l local_oid (command git $git_context rev-parse --verify --quiet "refs/heads/$branch^{commit}")
+            if test $status -ne 0
+                echo "git: keeping $branch: local tip unavailable after $command_name" >&2
+                continue
+            end
+            if test "$local_oid" != "$upstream_oid"
+                echo "git: keeping $branch: local tip differs from its last upstream" >&2
+                continue
+            end
+
+            set -l worktree_list (command git $git_context worktree list --porcelain)
+            if test $status -ne 0
+                echo "git: keeping $branch: worktree list failed after $command_name" >&2
+                continue
+            end
+            set -l branch_worktrees (string match -- "branch refs/heads/$branch" $worktree_list)
+            if test (count $branch_worktrees) -gt 1
+                echo "git: keeping $branch: branch is checked out in multiple worktrees" >&2
+                continue
+            end
+
+            set -l wt (command git $git_context for-each-ref --format='%(worktreepath)' "refs/heads/$branch" | string collect)
+            set -l worktree_lookup_status $pipestatus[1]
+            if test $worktree_lookup_status -ne 0
+                echo "git: keeping $branch: worktree lookup failed after $command_name" >&2
+                continue
+            end
+            if test -n "$wt"
+                set -l index_state (command git -C "$wt" ls-files -v)
+                if test $status -ne 0
+                    echo "git: keeping $branch: worktree index lookup failed after $command_name" >&2
+                    continue
+                end
+                if string match -rq -- '^[a-zS] ' $index_state
+                    echo "git: keeping $branch: worktree index hides file changes" >&2
+                    continue
+                end
+                set -l worktree_state (command git -C "$wt" status --porcelain --untracked-files=all --ignored --ignore-submodules=none)
+                if test $status -ne 0
+                    echo "git: keeping $branch: worktree status failed after $command_name" >&2
+                    continue
+                end
+                if test (count $worktree_state) -gt 0
+                    echo "git: keeping $branch: worktree contains local files or changes" >&2
+                    continue
+                end
+                command git $git_context worktree remove "$wt"
+                or continue
+            end
+            command git $git_context update-ref -d "refs/heads/$branch" "$upstream_oid"
+            or echo "git: keeping $branch: local tip changed during cleanup" >&2
+        end
+    end
+
+    return $command_status
+end
diff --git a/fish/config.fish b/fish/config.fish
index 6efb3bfd..3d04412d 100644
--- a/fish/config.fish
+++ b/fish/config.fish
@@ -36,20 +36,3 @@ if not string match -q -- $PNPM_HOME $PATH
     set -gx PATH "$PNPM_HOME" $PATH
 end
 # pnpm end
-
-# purge local branches whose upstream was deleted ([gone]) after every fetch/pull
-# only branches that HAD an upstream now gone are pruned — never-pushed work is left untouched
-function git
-    command git $argv
-    if test (count $argv) -gt 0; and contains -- $argv[1] fetch pull
-        # --prune marks deleted upstreams as [gone] in `git branch -vv`
-        command git fetch --prune 2>/dev/null
-        for branch in (command git branch -vv | grep ': gone]' | string replace -r '^[ *+]+(\S+).*' '$1' | grep -vE '^(main|development|staging)$')
-            set wt (command git worktree list 2>/dev/null | grep "\[$branch\]" | awk '{print $1}')
-            if test -n "$wt"
-                command git worktree remove --force $wt 2>/dev/null
-            end
-            command git branch -D $branch 2>/dev/null
-        end
-    end
-end
diff --git a/fish/tests/git_wrapper_test.fish b/fish/tests/git_wrapper_test.fish
new file mode 100644
index 00000000..f714b383
--- /dev/null
+++ b/fish/tests/git_wrapper_test.fish
@@ -0,0 +1,316 @@
+set -g project_root (path resolve (path dirname (status filename))/../..)
+set -g test_root (mktemp -d)
+
+function fail --argument-names message
+    echo "not ok - $message" >&2
+    exit 1
+end
+
+test -n "$test_root"; and test -d "$test_root"
+or fail "mktemp did not create the test directory"
+
+function cleanup --on-event fish_exit
+    command rm -rf -- "$test_root"
+    or echo "not ok - failed to remove $test_root" >&2
+end
+
+function must
+    command $argv
+    or begin
+        set -l rendered_command (string join ' ' -- $argv)
+        fail "command failed: $rendered_command"
+    end
+end
+
+set -gx _ZO_DATA_DIR "$test_root/zoxide"
+must mkdir "$test_root/zoxide"
+
+function create_repository --argument-names name
+    set -g remote_path "$test_root/$name.git"
+    set -g repository_path "$test_root/$name"
+    must git init --bare --quiet "$remote_path"
+    must git init --quiet --initial-branch=main "$repository_path"
+    must git -C "$repository_path" config user.email test@example.com
+    must git -C "$repository_path" config user.name Test
+    must git -C "$repository_path" remote add origin "$remote_path"
+    echo base >"$repository_path/file"
+    must git -C "$repository_path" add file
+    must git -C "$repository_path" commit --quiet --message base
+    must git -C "$repository_path" push --quiet --set-upstream origin main
+end
+
+function create_tracked_branch --argument-names branch
+    must git -C "$repository_path" switch --quiet --create "$branch"
+    echo "$branch" >"$repository_path/file"
+    must git -C "$repository_path" commit --quiet --all --message "$branch"
+    must git -C "$repository_path" push --quiet --set-upstream origin "$branch"
+    must git -C "$repository_path" switch --quiet main
+end
+
+source "$project_root/fish/conf.d/git-wrapper.fish"
+or fail "could not source fish/conf.d/git-wrapper.fish"
+
+create_repository divergent-branch
+create_tracked_branch feature
+must git -C "$repository_path" switch --quiet feature
+echo local >>"$repository_path/file"
+must git -C "$repository_path" commit --quiet --all --message local
+must git -C "$repository_path" switch --quiet main
+must git --git-dir="$remote_path" update-ref -d refs/heads/feature
+
+cd "$repository_path"
+or fail "could not enter $repository_path"
+git fetch
+or fail "fetch failed in divergent-branch"
+
+command git show-ref --verify --quiet refs/heads/feature
+or fail "fetch preserves a branch with local commits"
+
+echo "ok - fetch preserves a branch with local commits"
+
+create_repository clean-worktree
+create_tracked_branch feature
+set -l worktree_path "$test_root/clean-feature"
+must git -C "$repository_path" worktree add --quiet "$worktree_path" feature
+must git --git-dir="$remote_path" update-ref -d refs/heads/feature
+
+cd "$repository_path"
+or fail "could not enter $repository_path"
+git fetch
+or fail "fetch failed in clean-worktree"
+
+not test -e "$worktree_path"
+or fail "fetch removes a clean worktree without local commits"
+not command git show-ref --verify --quiet refs/heads/feature
+or fail "fetch removes a branch without local commits"
+
+echo "ok - fetch removes a clean worktree and branch without local commits"
+
+create_repository dirty-worktree
+create_tracked_branch feature
+set worktree_path "$test_root/dirty-feature"
+must git -C "$repository_path" worktree add --quiet "$worktree_path" feature
+echo dirty >>"$worktree_path/file"
+echo untracked >"$worktree_path/untracked"
+must git --git-dir="$remote_path" update-ref -d refs/heads/feature
+
+cd "$repository_path"
+or fail "could not enter $repository_path"
+set -l fetch_output (git fetch 2>&1)
+or fail "fetch failed in dirty-worktree"
+
+test -e "$worktree_path"
+or fail "fetch preserves a dirty worktree"
+command git show-ref --verify --quiet refs/heads/feature
+or fail "fetch preserves the branch of a dirty worktree"
+string match --quiet -- '*dirty*' (command git -C "$worktree_path" diff)
+or fail "fetch preserves uncommitted worktree changes"
+test -e "$worktree_path/untracked"
+or fail "fetch preserves untracked worktree files"
+string match --quiet -- '*worktree contains local files or changes*' $fetch_output
+or fail "fetch reports why a dirty worktree is preserved"
+
+echo "ok - fetch preserves a dirty worktree and branch"
+
+create_repository ignored-worktree
+create_tracked_branch feature
+must git -C "$repository_path" switch --quiet feature
+echo ignored >"$repository_path/.gitignore"
+must git -C "$repository_path" add .gitignore
+must git -C "$repository_path" commit --quiet --message ignore
+must git -C "$repository_path" push --quiet
+must git -C "$repository_path" switch --quiet main
+set worktree_path "$test_root/ignored-feature"
+must git -C "$repository_path" worktree add --quiet "$worktree_path" feature
+echo local >"$worktree_path/ignored"
+must git --git-dir="$remote_path" update-ref -d refs/heads/feature
+
+cd "$repository_path"
+or fail "could not enter $repository_path"
+set fetch_output (git fetch 2>&1)
+or fail "fetch failed in ignored-worktree"
+
+test -e "$worktree_path/ignored"
+or fail "fetch preserves ignored worktree files"
+command git show-ref --verify --quiet refs/heads/feature
+or fail "fetch preserves the branch of a worktree with ignored files"
+
+echo "ok - fetch preserves a worktree with ignored files"
+
+create_repository assume-unchanged-worktree
+create_tracked_branch feature
+set worktree_path "$test_root/assume-unchanged-feature"
+must git -C "$repository_path" worktree add --quiet "$worktree_path" feature
+must git -C "$worktree_path" update-index --assume-unchanged file
+echo local >>"$worktree_path/file"
+must git --git-dir="$remote_path" update-ref -d refs/heads/feature
+
+cd "$repository_path"
+or fail "could not enter $repository_path"
+set fetch_output (git fetch 2>&1)
+or fail "fetch failed in assume-unchanged-worktree"
+
+test -e "$worktree_path/file"
+or fail "fetch preserves assume-unchanged worktree changes"
+command git show-ref --verify --quiet refs/heads/feature
+or fail "fetch preserves the branch of an assume-unchanged worktree"
+
+echo "ok - fetch preserves an assume-unchanged worktree"
+
+create_repository skip-worktree
+create_tracked_branch feature
+set worktree_path "$test_root/skip-worktree-feature"
+must git -C "$repository_path" worktree add --quiet "$worktree_path" feature
+must git -C "$worktree_path" update-index --skip-worktree file
+must git --git-dir="$remote_path" update-ref -d refs/heads/feature
+
+cd "$repository_path"
+or fail "could not enter $repository_path"
+set fetch_output (git fetch 2>&1)
+or fail "fetch failed in skip-worktree"
+
+test -e "$worktree_path/file"
+or fail "fetch preserves a skip-worktree worktree"
+command git show-ref --verify --quiet refs/heads/feature
+or fail "fetch preserves the branch of a skip-worktree worktree"
+
+echo "ok - fetch preserves a skip-worktree worktree"
+
+create_repository multiple-worktrees
+create_tracked_branch feature
+set -l first_worktree_path "$test_root/first-feature"
+set -l second_worktree_path "$test_root/second-feature"
+must git -C "$repository_path" worktree add --quiet "$first_worktree_path" feature
+must git -C "$repository_path" worktree add --quiet --force "$second_worktree_path" feature
+must git --git-dir="$remote_path" update-ref -d refs/heads/feature
+
+cd "$repository_path"
+or fail "could not enter $repository_path"
+set fetch_output (git fetch 2>&1)
+or fail "fetch failed in multiple-worktrees"
+
+test -e "$first_worktree_path/file"
+or fail "fetch preserves the first of multiple worktrees"
+test -e "$second_worktree_path/file"
+or fail "fetch preserves the second of multiple worktrees"
+command git show-ref --verify --quiet refs/heads/feature
+or fail "fetch preserves a branch checked out in multiple worktrees"
+
+echo "ok - fetch preserves a branch checked out in multiple worktrees"
+
+create_repository failed-fetch
+create_tracked_branch feature
+must git --git-dir="$remote_path" update-ref -d refs/heads/feature
+
+cd "$repository_path"
+or fail "could not enter $repository_path"
+set -l failed_fetch_output (git fetch missing 2>&1)
+set -l fetch_status $status
+
+test $fetch_status -ne 0
+or fail "fetch preserves the original failure status, got $fetch_status"
+string match --quiet -- '*does not appear to be a git repository*' $failed_fetch_output
+or fail "failed fetch keeps its error visible"
+command git show-ref --verify --quiet refs/heads/feature
+or fail "failed fetch does not clean branches"
+
+echo "ok - failed fetch preserves its status and branches"
+
+create_repository dry-run
+create_tracked_branch feature
+must git --git-dir="$remote_path" update-ref -d refs/heads/feature
+
+cd "$repository_path"
+or fail "could not enter $repository_path"
+git fetch --dry-run
+or fail "dry-run fetch failed"
+
+command git show-ref --verify --quiet refs/heads/feature
+or fail "dry-run fetch does not clean branches"
+command git show-ref --verify --quiet refs/remotes/origin/feature
+or fail "dry-run fetch does not prune remote-tracking branches"
+
+echo "ok - dry-run fetch leaves branches unchanged"
+
+create_repository unavailable-upstream
+create_tracked_branch feature
+must git --git-dir="$remote_path" update-ref -d refs/heads/feature
+must git -C "$repository_path" update-ref -d refs/remotes/origin/feature
+
+cd "$repository_path"
+or fail "could not enter $repository_path"
+set fetch_output (git fetch 2>&1)
+or fail "fetch failed in unavailable-upstream"
+
+command git show-ref --verify --quiet refs/heads/feature
+or fail "fetch preserves a branch when its previous upstream tip is unavailable"
+string match --quiet -- '*upstream tip unavailable*' $fetch_output
+or fail "fetch reports an unavailable previous upstream tip"
+
+echo "ok - unavailable upstream tip preserves the branch"
+
+create_repository single-fetch
+create_tracked_branch feature
+must git -C "$repository_path" remote add backup "$remote_path"
+must git --git-dir="$remote_path" update-ref -d refs/heads/feature
+must git -C "$repository_path" remote set-url origin "$test_root/missing.git"
+
+cd "$repository_path"
+or fail "could not enter $repository_path"
+set fetch_output (git fetch backup 2>&1)
+set fetch_status $status
+
+test $fetch_status -eq 0
+or fail "fetching another remote succeeds, got $fetch_status"
+command git show-ref --verify --quiet refs/heads/feature
+or fail "fetching another remote preserves branches tracking origin"
+not string match --quiet -- '*does not appear to be a git repository*' $fetch_output
+or fail "fetch does not contact an unrequested remote"
+
+echo "ok - fetch contacts only the requested remote"
+
+create_repository pull
+create_tracked_branch feature
+must git --git-dir="$remote_path" update-ref -d refs/heads/feature
+
+cd "$repository_path"
+or fail "could not enter $repository_path"
+git pull --ff-only
+or fail "pull failed"
+
+not command git show-ref --verify --quiet refs/heads/feature
+or fail "pull removes a branch without local commits"
+
+echo "ok - pull removes a branch without local commits"
+
+create_repository global-options
+create_tracked_branch feature
+must git --git-dir="$remote_path" update-ref -d refs/heads/feature
+
+cd "$test_root"
+or fail "could not enter $test_root"
+git --no-pager -C "$repository_path" fetch
+or fail "fetch with global options failed"
+
+not command git -C "$repository_path" show-ref --verify --quiet refs/heads/feature
+or fail "fetch with global options removes a branch without local commits"
+
+echo "ok - fetch with global options removes a branch without local commits"
+
+for primary_branch in master trunk
+    create_repository "primary-$primary_branch"
+    must git -C "$repository_path" branch --move "$primary_branch"
+    must git -C "$repository_path" push --quiet --set-upstream origin "$primary_branch"
+    must git -C "$repository_path" switch --quiet --create parking
+    must git --git-dir="$remote_path" update-ref -d "refs/heads/$primary_branch"
+
+    cd "$repository_path"
+    or fail "could not enter $repository_path"
+    git fetch
+    or fail "fetch failed for primary branch $primary_branch"
+
+    command git show-ref --verify --quiet "refs/heads/$primary_branch"
+    or fail "fetch preserves primary branch $primary_branch"
+end
+
+echo "ok - fetch preserves dynamically detected primary branches"
diff --git a/scripts/git_main_branch b/scripts/git_main_branch
index c8cc85be..715a44c7 100755
--- a/scripts/git_main_branch
+++ b/scripts/git_main_branch
@@ -1,16 +1,30 @@
 #!/usr/bin/env bash
 
+strict=
+if [[ ${1-} == "--strict" ]]; then
+  strict=1
+  shift
+fi
+
 # Check if we're in a git repository
-if ! command git rev-parse --git-dir &>/dev/null; then
+if ! command git "$@" rev-parse --git-dir &>/dev/null; then
+  if [[ -n $strict ]]; then
+    exit 1
+  fi
   echo "main"
   exit 0
 fi
 
 # Try common branch names that exist locally
 for branch in main master trunk; do
-  if git show-ref -q --verify "refs/heads/$branch" 2>/dev/null; then
+  if git "$@" show-ref -q --verify "refs/heads/$branch" 2>/dev/null; then
     echo "$branch"
     exit 0
+  else
+    show_ref_status=$?
+    if [[ $show_ref_status -ne 1 && -n $strict ]]; then
+      exit "$show_ref_status"
+    fi
   fi
 done