Drop the last two references to retired template variables

`template_references_repo_name` in the bare-repo `worktree-path` offer still
ORed `template_references_var(template, "main_worktree")`, and a unit case
pinned that arm as `true`. The template it inspects comes from the loaded
config, which the deprecation layer has already renamed, so the arm can no
longer match — dead logic that contradicts the premise of the change.

`wt config show-theme`'s shell-highlighting sample also still rendered
`cp {{ repo_root }}/target {{ worktree }}/target`, i.e. user-visible output
advertising two names that now fail expansion. Its snapshot moves with it.

src/commands/configure_shell.rs

@@ -1634,7 +1634,7 @@ pub fn handle_show_theme() {
     eprintln!(
         "{}",
         format_bash_with_gutter(
-            "eval \"$(wt config shell init bash)\"\necho 'This is a long command that will wrap to the next line when the terminal is narrow enough to require wrapping.'\necho 'hello\nworld'\ncargo build --release &&\ncargo test\ncp {{ repo_root }}/target {{ worktree }}/target"
+            "eval \"$(wt config shell init bash)\"\necho 'This is a long command that will wrap to the next line when the terminal is narrow enough to require wrapping.'\necho 'hello\nworld'\ncargo build --release &&\ncargo test\ncp {{ repo_path }}/target {{ worktree_path }}/target"
         )
     );
 

src/commands/worktree/resolve.rs

@@ -117,10 +117,12 @@ pub fn worktree_display_name(
 /// Uses an absolute path (`repo_path`/../) to avoid ambiguity with relative resolution.
 const BARE_REPO_WORKTREE_PATH: &str = "{{ repo_path }}/../{{ branch | sanitize }}";
 
-/// Check whether a template string references `{{ repo }}` or `{{ main_worktree }}`.
+/// Check whether a template string references `{{ repo }}`.
+///
+/// The template comes from the loaded config, so the deprecation layer has
+/// already renamed the retired `main_worktree` to `repo` before it gets here.
 fn template_references_repo_name(template: &str) -> bool {
     worktrunk::config::template_references_var(template, "repo")
-        || worktrunk::config::template_references_var(template, "main_worktree")
 }
 
 /// Offer to set a project-level `worktree-path` for bare repos with hidden directory names.
@@ -281,11 +283,6 @@ mod tests {
                 true,
             ),
             ("repo with filter", "{{ repo | sanitize }}", true),
-            (
-                "deprecated main_worktree alias",
-                "{{ main_worktree }}.{{ branch }}",
-                true,
-            ),
             (
                 "repo_path is a distinct variable",
                 "{{ repo_path }}/../{{ branch | sanitize }}",

tests/integration_tests/snapshots/integration__integration_tests__config_show_theme__show_theme.snap

@@ -66,7 +66,7 @@ exit_code: 0
   world'
   cargo build --release &&
   cargo test
-  cp {{ repo_root }}/target {{ worktree }}/target
+  cp {{ repo_path }}/target {{ worktree_path }}/target
 
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