chore(dist): compile PRs #60/#61 into soul.c

- PR #60: inject operator home dir into system prompt (#30)
  Adds OPERATOR IDENTITY section so the LLM correctly resolves
  'my files/notes/desktop' to the actual running user's $HOME.
  Prevents identity confusion between imprint author and operator.

- PR #61: plan-mode endpoint POST /api/chat {mode:'plan'} (#27)
  Adds handle_chat_plan — returns {steps:[{id,title,detail}]} JSON.
  Wired into all three /api/chat route handlers. Grounds the plan
  via engram_compile (same as agentic path) for context awareness.

dist changes:
  - soul.c: both PRs compiled in; build_system_prompt updated to
    2-param signature (ctx, chat_mode); handle_chat_plan added
  - chat.c/routes.c/chat.elh: individual module outputs updated
  - elp-c-decls.h: remove stale 1-param build_system_prompt decl,
    add handle_chat_plan declaration
  - soul.elh.c: new soul header declarations file (from PR #60)

Compile verified: cc -O2 -DHAVE_CURL soul.c el_runtime.c -lcurl
Binary: 805K arm64, smoke test passes (port in use = expected).

dist/chat.elh

@@ -43,6 +43,7 @@ extern fn resolve_in_root(path: String, root: String) -> String
 extern fn dispatch_tool(tool_name: String, tool_input: String) -> String
 extern fn is_builtin_tool(tool_name: String) -> Bool
 extern fn next_bridge_id() -> String
+extern fn handle_chat_plan(body: String) -> String
 extern fn handle_chat_agentic(body: String) -> String
 extern fn agentic_loop(session_id: String, model: String, safe_sys: String, tools_json: String, messages_in: String, h: Map, tools_log_in: String) -> String
 extern fn bridge_save(session_id: String, model: String, safe_sys: String, tools_json: String, messages: String, tools_log: String, tool_use_id: String) -> Bool