document "R" will upgrade tui from quote->portfolio operations

docs/reference/tui.md

@@ -29,6 +29,12 @@ currently-selected symbol.
 The symbol-scoped tabs follow a single "current symbol"; change it from
 the Portfolio tab (select a holding) or by launching with `-s`.
 
+When you launch on a symbol (`zfin i -s AAPL`), no portfolio is loaded,
+so the portfolio-scoped tabs (Portfolio, Analysis, Review, Projections,
+History) are greyed out and unselectable - you start on the Quote tab.
+Press `R` to load your portfolio on demand: this "upgrades" the session
+into the full portfolio view and enables those tabs.
+
 ## Charts
 
 Tabs with charts render high-fidelity **Kitty graphics** when your
@@ -46,6 +52,7 @@ current bindings). The global defaults:
 |----------------------------------------------|--------------------------------|
 | `q`, `Ctrl-C`                                | Quit                           |
 | `r`, `F5`                                    | Refresh the current tab's data |
+| `R`                                          | Reload the portfolio from disk |
 | `l` / `right` / `tab`                        | Next tab                       |
 | `h` / `left` / `shift+tab`                   | Previous tab                   |
 | `1`-`8`                                      | Jump to a tab by number        |

src/PortfolioData.zig

@@ -458,6 +458,11 @@ pub fn invalidateClassificationMap(self: *PortfolioData) void {
 /// 'K' overlay) to show the `metadata.srf` security name the way the CLI
 /// `quote` command does. No-op when `paths_in` is empty or a portfolio
 /// is already loaded (a full `load()` populates the map itself).
+///
+/// Intentional side effect: capturing `paths_in` here also lets the `R`
+/// (reload_portfolio) key run a first full `load()` from symbol mode -
+/// see `portfolio_tab.reloadPortfolioFile` - so the user can "upgrade" a
+/// symbol-only session into the full portfolio view on demand.
 pub fn primeClassificationMap(self: *PortfolioData, paths_in: []const []const u8) void {
     if (paths_in.len == 0 or self.paths.len != 0) return;
 

src/tui/portfolio_tab.zig

@@ -1910,6 +1910,17 @@ pub fn buildWelcomeScreenLines(
 /// Inactive tabs stay in `loaded = false` and lazy-rebuild on
 /// next switch.
 pub fn reloadPortfolioFile(state: *State, app: *App) void {
+    // `paths` is non-empty once a portfolio has been resolved - either
+    // by a normal load, OR by the symbol-mode classification-map prime
+    // (see PortfolioData.primeClassificationMap). In that second case
+    // `file` is still null (no portfolio actually loaded yet), and the
+    // `pd.reload` below runs the FIRST full load. That's intentional:
+    // `R` lets you "upgrade" a symbol-only session (`zfin -s AAPL`)
+    // into the full portfolio view, lighting up the portfolio-scoped
+    // tabs. Only when nothing has been resolved at all (no portfolio
+    // file on disk) is `paths` empty and there's genuinely nothing to
+    // do. Do NOT tighten this to `file == null` - that would break the
+    // upgrade path.
     if (app.portfolio.paths.len == 0) {
         app.setStatus("No portfolio file to reload");
         return;