fix(profiles): cross-profile soft guard on file-write tools + system-prompt hint (#31290)

* fix(profiles): cross-profile soft guard on file-write tools + system-prompt hint

Adds a soft guard so an agent running under one Hermes profile cannot
silently edit a different profile's skills/plugins/cron/memories.
Three layers:

A. agent/file_safety.classify_cross_profile_target
   Classifies a write target against the active HERMES_HOME. Returns
   a {active_profile, target_profile, area, target_path} dict when the
   path lands in another profile's scoped area. PROFILE_SCOPED_AREAS =
   (skills, plugins, cron, memories). get_cross_profile_warning()
   wraps it into a model-facing error string that names both profiles,
   names the area, and points at the cross_profile=True bypass.

   Defense-in-depth, NOT a security boundary — the terminal tool runs
   as the same OS user and can write any of these paths directly. The
   guard exists to prevent confused-agent corruption, not to stop a
   determined attacker. SECURITY.md §3.2 (terminal-bypass posture)
   still applies.

   Wired into tools/file_tools.write_file_tool and patch_tool with a
   cross_profile=False kwarg. WRITE_FILE_SCHEMA and PATCH_SCHEMA both
   advertise cross_profile so the model can pass it after explicit
   user direction. patch_tool extracts target paths from V4A patch
   bodies before checking (same shape as the existing sensitive-path
   check).

   skill_manage is already scoped to the active profile's SKILLS_DIR
   by construction, so no extra guard wiring is needed there. The
   D-side error message (below) still names other profiles when the
   skill exists elsewhere.

B. agent/system_prompt
   One deterministic line near the environment-hints block names the
   active profile and tells the model not to modify another profile's
   skills/plugins/cron/memories without explicit direction. Profile
   name is stable for the lifetime of the AIAgent, so the line is
   prompt-cache-safe.

D. tools/skill_manager_tool._skill_not_found_error
   Replaces the bare "Skill 'X' not found." with a message that:
     - names the active profile,
     - searches OTHER profiles' skills dirs for the same name,
     - names the profile(s) where the skill exists and the path,
     - suggests `hermes -p <name>` to switch profiles, or
       cross_profile=True for an explicit edit.

   All 5 "not found" sites in skill_manager_tool (edit, patch, delete,
   write_file, remove_file) now go through the helper.

Reference incident (May 2026): a hermes-security profile session
edited skills under both ~/.hermes/profiles/hermes-security/skills/
AND ~/.hermes/skills/ (the default profile's skills) without
realizing the second path belonged to a different profile. Three of
the four skill files needed manual restoration afterward.

What this PR does NOT do:

  * No hard block. The terminal tool can still touch any of these
    paths with no guard — same posture as the dangerous-command
    approval flow. SECURITY.md §3.2 applies.
  * No regex sweep on terminal commands for cross-profile paths.
    That direction is a Skills-Guard-style arms race (cd + relative
    paths, base64, etc.) and would false-positive on legitimate
    cross-profile reads. Filed as a follow-up.
  * No on-disk path migration. ~/.hermes/skills/ remains the
    default profile's skills dir; this PR is about telling the
    agent about that boundary, not changing the layout.

Tests:
  tests/agent/test_file_safety_cross_profile.py (16 tests)
    - _resolve_active_profile_name covers default/named/failure paths
    - classify_cross_profile_target covers all four scoped areas,
      both directions (default → named, named → default, named → named),
      non-Hermes paths, and root-level config files
    - get_cross_profile_warning covers in-profile no-op, cross-profile
      message shape, and the defense-in-depth self-documentation

  tests/tools/test_cross_profile_guard.py (12 tests)
    - write_file: in-profile allow, cross-profile block, cross_profile=True
      bypass, non-Hermes pass-through
    - patch: replace-mode block, cross_profile=True bypass, V4A patch
      path extraction
    - skill_manage: error names the other profile (single + multiple),
      missing-everywhere falls back to skills_list hint
    - system prompt: contract-level checks (both branches present,
      cross_profile=True mentioned, ~/.hermes/profiles/ referenced)

All 207 existing tests in file_safety/file_operations/skill_manager
still pass. 10 system-prompt tests still pass.

E2E verified: the exact incident scenario (security profile editing
default's hermes-agent-dev skill) is now blocked with the warning
message; cross_profile=True unblocks.

* fix(code_execution): add cross_profile to write_file/patch stubs

The cross_profile kwarg added to write_file_tool/patch_tool needs to
flow through the execute_code sandbox stubs in _TOOL_STUBS so the
test_stubs_cover_all_schema_params drift test passes. Without this,
scripts running inside execute_code couldn't pass cross_profile=True
through hermes_tools.write_file().

Caught by CI on PR #31290.

agent/system_prompt.py

@@ -205,6 +205,40 @@ def build_system_prompt_parts(agent: Any, system_message: Optional[str] = None)
     if _env_hints:
         stable_parts.append(_env_hints)
 
+    # Active-profile hint — names the Hermes profile the agent is running
+    # under so it doesn't conflate ~/.hermes/skills/ (default profile) with
+    # ~/.hermes/profiles/<active>/skills/ (this profile's). Deterministic
+    # for the lifetime of the agent — profile name doesn't change
+    # mid-session, so this doesn't break the prompt cache.
+    # See file_safety._resolve_active_profile_name + classify_cross_profile_target
+    # for the matching tool-side guard.
+    try:
+        from agent.file_safety import _resolve_active_profile_name
+        active_profile = _resolve_active_profile_name()
+    except Exception:
+        active_profile = "default"
+    if active_profile == "default":
+        stable_parts.append(
+            "Active Hermes profile: default. Other profiles (if any) live "
+            "under ~/.hermes/profiles/<name>/. Each profile has its own "
+            "skills/, plugins/, cron/, and memories/ that affect a different "
+            "session than this one. Do not modify another profile's "
+            "skills/plugins/cron/memories unless the user explicitly directs "
+            "you to."
+        )
+    else:
+        stable_parts.append(
+            f"Active Hermes profile: {active_profile}. This session reads "
+            f"and writes ~/.hermes/profiles/{active_profile}/. The default "
+            f"profile's data lives at ~/.hermes/skills/, ~/.hermes/plugins/, "
+            f"~/.hermes/cron/, ~/.hermes/memories/ — those belong to a "
+            f"different session run from a different shell. Do NOT modify "
+            f"another profile's skills/plugins/cron/memories unless the user "
+            f"explicitly directs you to. The cross-profile write guard will "
+            f"refuse such writes by default; pass cross_profile=True only "
+            f"after explicit direction."
+        )
+
     platform_key = (agent.platform or "").lower().strip()
     if platform_key in PLATFORM_HINTS:
         stable_parts.append(PLATFORM_HINTS[platform_key])