refactor: modular architecture v3.0 + SEC filing viewer fix + README

Architecture (3,909-line monolith → 28 focused modules, all < 300 lines):
- config/: constants.py (company lists, row maps, Damodaran baselines), theme.py (CSS/HTML)
- utils/: prefs, formatting, ticker, dcf, charts, ui_helpers
- data/: sec_parser, sec_fetcher, sec_downloader, financials, fundamentals,
         valuation, ratios, scores, scores_ai, market
- ai/: gemini_core, gemini_sec, gemini_insights
- views/: sidebar, tab1_quant, tab1_ai, tab1_filings, tab2_dcf,
          tab3_comps, tab4_news, tab5_markets, tab6_crypto, tab7_technical
- app.py: thin orchestrator (~118 lines)
- Strict unidirectional dependency graph (no circular imports)
- All @st.cache_data TTLs and st.session_state keys preserved identically

SEC filing viewer fix:
- Rebuilt EDGAR fetch chain: company_tickers.json → CIK → submissions API
  → filings.recent.primaryDocument[] (replaces deprecated directory.item)
- Filing type selectbox (10-K, 10-Q, 8-K, 20-F, 6-K) connected to backend
- Native HTML rendered via streamlit.components.v1.html() with CSS reset
- Errors surfaced explicitly with st.error()
- DART direct links restored for Korean-listed companies

.gitignore: data/ → data/*.json + data/*.html (preserve Python modules)
README: full rewrite for master's portfolio — 7-tab layout, architecture
diagram, modular structure tree, technical challenges, design rationale

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

views/sidebar.py

@@ -0,0 +1,142 @@
+import os
+import streamlit as st
+from utils.prefs import _load_prefs, _save_prefs, _PREFS_PATH
+from utils.ticker import infer_market_from_ticker
+
+try:
+    from yahooquery import search as yq_search
+except ImportError:
+    yq_search = None
+
+
+def render_sidebar():
+    with st.sidebar:
+        st.markdown("""
+<div style="display: flex; align-items: center; gap: 8px; margin-bottom: 16px; padding-bottom: 12px; border-bottom: 1px solid rgba(255,255,255,0.06);">
+    <span style="font-size: 1.3rem; font-weight: 800; color: #60A5FA; font-family: 'JetBrains Mono', monospace;">ATLAS</span>
+    <span style="font-size: 1.3rem; font-weight: 300; color: #6B7280;">TERMINAL</span>
+</div>
+""", unsafe_allow_html=True)
+        st.markdown('<div style="color: #6B7280; font-size: 0.7rem; font-weight: 600; letter-spacing: 2px; margin-bottom: 8px;">SETTINGS</div>', unsafe_allow_html=True)
+        _prefs = _load_prefs()
+        # Restore last selected company on refresh (session_state is empty after reload)
+        if _prefs.get("last_ticker") and not st.session_state.get("company_search_options"):
+            _lt = _prefs["last_ticker"]
+            _opts = _prefs.get("last_company_options") or []
+            _syms = _prefs.get("last_company_symbols") or []
+            if not _opts and _lt:
+                _opts = [f"[Saved] {_lt}"]
+                _syms = [_lt]
+            st.session_state["ticker"] = _lt
+            st.session_state["company_search_options"] = _opts
+            st.session_state["company_search_symbols"] = _syms
+        _default_key = _prefs.get("google_api_key") or os.environ.get("GOOGLE_API_KEY", "")
+        _default_email = _prefs.get("sec_email") or os.environ.get("SEC_EDGAR_EMAIL", "")
+        google_api_key = st.text_input(
+            "Google API Key (Gemini)",
+            value=_default_key,
+            help="Required for Tab 1 (10-K insights).",
+            key="input_google_api_key",
+        )
+        sec_email = st.text_input(
+            "SEC EDGAR Email",
+            value=_default_email,
+            help="Required for 10-K download.",
+            key="input_sec_email",
+        )
+        remember_me = st.checkbox(
+            "Remember API key & email (save locally)",
+            value=bool(_prefs),
+            help="Store in .app_prefs.json in this project. Uncheck to clear and stop saving.",
+            key="remember_me",
+        )
+        if remember_me and (google_api_key or sec_email):
+            _save_prefs(google_api_key, sec_email)
+        elif not remember_me and _PREFS_PATH.exists():
+            # Clear only API keys in prefs; keep last_ticker so company selection persists on refresh
+            try:
+                _cur = _load_prefs()
+                _save_prefs("", "", last_ticker=_cur.get("last_ticker"), last_company_options=_cur.get("last_company_options"), last_company_symbols=_cur.get("last_company_symbols"))
+            except Exception:
+                pass
+        st.markdown('<div style="color: #6B7280; font-size: 0.7rem; font-weight: 600; letter-spacing: 2px; margin: 16px 0 8px;">COMPANY SEARCH</div>', unsafe_allow_html=True)
+        search_query = st.text_input(
+            "Search Company Name (e.g., Apple, 삼성, Mitsubishi)",
+            value=st.session_state.get("company_search_input", ""),
+            key="company_search_input",
+            placeholder="e.g. Apple, 삼성, Mitsubishi",
+        )
+        if st.button("Search Company", key="search_company_btn"):
+            query = (search_query or "").strip()
+            if not query:
+                st.warning("Enter a company name to search.")
+            elif yq_search is None:
+                st.warning("yahooquery is not installed; search is unavailable.")
+            else:
+                try:
+                    raw_results = yq_search(query)
+                    if not isinstance(raw_results, dict):
+                        raw_results = {}
+                    quotes = raw_results.get("quotes", []) or []
+                    skip_types = ("INDEX", "MUTUALFUND")
+                    quotes = [
+                        q for q in quotes
+                        if q.get("symbol") and q.get("shortname")
+                        and (q.get("quoteType") or "EQUITY") not in skip_types
+                    ]
+                    if not quotes:
+                        st.session_state["company_search_options"] = []
+                        st.session_state["company_search_symbols"] = []
+                        st.warning("No valid equities found. Try typing the English name (e.g., 'Samsung' instead of '삼성').")
+                    else:
+                        options = []
+                        symbols = []
+                        for q in quotes[:50]:
+                            sym = (q.get("symbol") or "").strip()
+                            options.append(f"[{q.get('exchange', 'N/A')}] {q.get('symbol')} - {q.get('shortname', 'Unknown')}")
+                            symbols.append(sym)
+                        st.session_state["company_search_options"] = options
+                        st.session_state["company_search_symbols"] = symbols
+                        st.session_state["ticker"] = symbols[0]
+                        st.success(f"Found {len(options)} result(s). Select below.")
+                except Exception:
+                    st.warning("No valid equities found. Try typing the English name (e.g., 'Samsung' instead of '삼성').")
+                    st.session_state["company_search_options"] = []
+                    st.session_state["company_search_symbols"] = []
+
+        search_options = st.session_state.get("company_search_options") or []
+        search_symbols = st.session_state.get("company_search_symbols") or []
+        placeholder = "— Click the search button above —"
+        options_for_select = [placeholder] if not search_options else search_options
+        current_ticker = st.session_state.get("ticker", "NVDA")
+        default_idx = 0
+        if search_symbols and current_ticker:
+            for i, sym in enumerate(search_symbols):
+                if sym == current_ticker:
+                    default_idx = i
+                    break
+        selected_option = st.selectbox(
+            "Select company (ticker - name)",
+            options=options_for_select,
+            index=0 if not search_options else min(default_idx, len(search_options) - 1),
+            key="company_select",
+        )
+        if search_options and selected_option and selected_option != placeholder and " - " in selected_option:
+            first_part = selected_option.split(" - ", 1)[0].strip()
+            sym = first_part.split("]", 1)[-1].strip() if "]" in first_part else first_part
+            st.session_state["ticker"] = sym
+        ticker = st.session_state.get("ticker") or (search_symbols[0] if search_symbols else "NVDA")
+        st.session_state["google_api_key"] = google_api_key
+        st.session_state["sec_email"] = sec_email
+        st.session_state["ticker"] = ticker
+        st.session_state["market"] = infer_market_from_ticker(ticker)
+        # Persist selected company so it survives page refresh
+        _save_prefs(
+            google_api_key if st.session_state.get("remember_me") else "",
+            sec_email if st.session_state.get("remember_me") else "",
+            last_ticker=ticker,
+            last_company_options=search_options,
+            last_company_symbols=search_symbols,
+        )
+        st.caption("Search by name (any language), then select. Ticker suffix is set automatically.")
+    return ticker