refactor: remove dead code — 1,784 lines across 77 files (#9180)

Deep scan with vulture, pyflakes, and manual cross-referencing identified:
- 41 dead functions/methods (zero callers in production)
- 7 production-dead functions (only test callers, tests deleted)
- 5 dead constants/variables
- ~35 unused imports across agent/, hermes_cli/, tools/, gateway/

Categories of dead code removed:
- Refactoring leftovers: _set_default_model, _setup_copilot_reasoning_selection,
  rebuild_lookups, clear_session_context, get_logs_dir, clear_session
- Unused API surface: search_models_dev, get_pricing, skills_categories,
  get_read_files_summary, clear_read_tracker, menu_labels, get_spinner_list
- Dead compatibility wrappers: schedule_cronjob, list_cronjobs, remove_cronjob
- Stale debug helpers: get_debug_session_info copies in 4 tool files
  (centralized version in debug_helpers.py already exists)
- Dead gateway methods: send_emote, send_notice (matrix), send_reaction
  (bluebubbles), _normalize_inbound_text (feishu), fetch_room_history
  (matrix), _start_typing_indicator (signal), parse_feishu_post_content
- Dead constants: NOUS_API_BASE_URL, SKILLS_TOOL_DESCRIPTION,
  FILE_TOOLS, VALID_ASPECT_RATIOS, MEMORY_DIR
- Unused UI code: _interactive_provider_selection,
  _interactive_model_selection (superseded by prompt_toolkit picker)

Test suite verified: 609 tests covering affected files all pass.
Tests for removed functions deleted. Tests using removed utilities
(clear_read_tracker, MEMORY_DIR) updated to use internal APIs directly.

agent/models_dev.py

@@ -18,10 +18,8 @@ Other modules should import the dataclasses and query functions from here
 rather than parsing the raw JSON themselves.
 """
 
-import difflib
 import json
 import logging
-import os
 import time
 from dataclasses import dataclass
 from pathlib import Path
@@ -177,13 +175,6 @@ PROVIDER_TO_MODELS_DEV: Dict[str, str] = {
 _MODELS_DEV_TO_PROVIDER: Optional[Dict[str, str]] = None
 
 
-def _get_reverse_mapping() -> Dict[str, str]:
-    """Return models.dev ID → Hermes provider ID mapping."""
-    global _MODELS_DEV_TO_PROVIDER
-    if _MODELS_DEV_TO_PROVIDER is None:
-        _MODELS_DEV_TO_PROVIDER = {v: k for k, v in PROVIDER_TO_MODELS_DEV.items()}
-    return _MODELS_DEV_TO_PROVIDER
-
 
 def _get_cache_path() -> Path:
     """Return path to disk cache file."""
@@ -464,93 +455,6 @@ def list_agentic_models(provider: str) -> List[str]:
     return result
 
 
-def search_models_dev(
-    query: str, provider: str = None, limit: int = 5
-) -> List[Dict[str, Any]]:
-    """Fuzzy search across models.dev catalog. Returns matching model entries.
-
-    Args:
-        query: Search string to match against model IDs.
-        provider: Optional Hermes provider ID to restrict search scope.
-                  If None, searches across all providers in PROVIDER_TO_MODELS_DEV.
-        limit: Maximum number of results to return.
-
-    Returns:
-        List of dicts, each containing 'provider', 'model_id', and the full
-        model 'entry' from models.dev.
-    """
-    data = fetch_models_dev()
-    if not data:
-        return []
-
-    # Build list of (provider_id, model_id, entry) candidates
-    candidates: List[tuple] = []
-
-    if provider is not None:
-        # Search only the specified provider
-        mdev_provider_id = PROVIDER_TO_MODELS_DEV.get(provider)
-        if not mdev_provider_id:
-            return []
-        provider_data = data.get(mdev_provider_id, {})
-        if isinstance(provider_data, dict):
-            models = provider_data.get("models", {})
-            if isinstance(models, dict):
-                for mid, mdata in models.items():
-                    candidates.append((provider, mid, mdata))
-    else:
-        # Search across all mapped providers
-        for hermes_prov, mdev_prov in PROVIDER_TO_MODELS_DEV.items():
-            provider_data = data.get(mdev_prov, {})
-            if isinstance(provider_data, dict):
-                models = provider_data.get("models", {})
-                if isinstance(models, dict):
-                    for mid, mdata in models.items():
-                        candidates.append((hermes_prov, mid, mdata))
-
-    if not candidates:
-        return []
-
-    # Use difflib for fuzzy matching — case-insensitive comparison
-    model_ids_lower = [c[1].lower() for c in candidates]
-    query_lower = query.lower()
-
-    # First try exact substring matches (more intuitive than pure edit-distance)
-    substring_matches = []
-    for prov, mid, mdata in candidates:
-        if query_lower in mid.lower():
-            substring_matches.append({"provider": prov, "model_id": mid, "entry": mdata})
-
-    # Then add difflib fuzzy matches for any remaining slots
-    fuzzy_ids = difflib.get_close_matches(
-        query_lower, model_ids_lower, n=limit * 2, cutoff=0.4
-    )
-
-    seen_ids: set = set()
-    results: List[Dict[str, Any]] = []
-
-    # Prioritize substring matches
-    for match in substring_matches:
-        key = (match["provider"], match["model_id"])
-        if key not in seen_ids:
-            seen_ids.add(key)
-            results.append(match)
-            if len(results) >= limit:
-                return results
-
-    # Add fuzzy matches
-    for fid in fuzzy_ids:
-        # Find original-case candidates matching this lowered ID
-        for prov, mid, mdata in candidates:
-            if mid.lower() == fid:
-                key = (prov, mid)
-                if key not in seen_ids:
-                    seen_ids.add(key)
-                    results.append({"provider": prov, "model_id": mid, "entry": mdata})
-                    if len(results) >= limit:
-                        return results
-
-    return results
-
 
 # ---------------------------------------------------------------------------
 # Rich dataclass constructors — parse raw models.dev JSON into dataclasses