fix(permissions): native path deny/ask rules apply to the file the tool opens

Edit/Read/Grep rules matched only the raw argument string, so a workspace
symlink (or a quoted, `~`, `./`, `..`, or absolute spelling) reached a
denied file. The policy now resolves the path exactly as the tools do
(sanitize, expand `~`, display-cwd remap, join to the requesting session's
cwd), follows symlinks parent-first, and re-checks deny/ask rules on the
opened path and its target as absolute, `./`-relative and relative
spellings. Escalation only: no allow is granted through a link. A link
that cannot be followed forces a prompt that survives YOLO, auto mode and
the session edit grant, with event reason `unresolved_link`.

Permission requests now carry the requesting tool's cwd and display cwd
so a child worktree session sharing its parent's handle is checked where
it runs.

Ported from upstream 1.0.14 (grok-build permission/policy.rs symlink
re-check), reshaped for Kigi's lexical rule matcher.

Claude-Session: https://claude.ai/code/session_01RUqV8HVGXcAETyYbZ2tPQ4

crates/codegen/kigi-shell/src/agent/mvp_agent/tests/subagent_spawn_context_tests.rs

@@ -27,7 +27,7 @@ async fn subagent_spawn_context_inherits_parent_permission_handle() {
                 kigi_workspace::permission::spawn_permission_manager(
                     sid.clone(),
                     gateway,
-                    cwd,
+                    cwd.clone(),
                     kigi_workspace::permission::types::ClientType::Generic,
                     Some(PermissionConfig::new(vec![PermissionRule {
                         action: RuleAction::Deny,
@@ -64,6 +64,8 @@ async fn subagent_spawn_context_inherits_parent_permission_handle() {
                         Some("child-session".to_owned()),
                         Some("general-purpose".to_owned()),
                         Some("permission inheritance regression".to_owned()),
+                        cwd.clone(),
+                        None,
                     )
                     .await;
                 assert!(