docs: document context-dialog interaction; correct Saved Points flow

README.md

@@ -235,59 +235,37 @@ Click **⚙ Preferences** in the top bar:
 
 ## Directions & Routing
 
-The flow is: pick an **origin**, open **Directions**, pick a **destination**,
+Everything starts from the map. Clicking one spot opens a **context dialog**;
-then **Calculate**.
+no click ever saves or routes automatically.
 
-1. **Pick the origin (start point)** — select any POI from **search**, or click
+- **Clicking an existing point** (a POI/zone/path, or a Saved Point) shows its
-   directly on the map. (Clicking empty space creates a browser-local *Saved
+  info and offers **"Directions from here"** - which sets it as the origin and
-   Point* and uses it as the origin.)
+  opens the destination picker - plus **"Directions to here"** once an origin
-2. The **Directions** button in the top bar is enabled only when an origin is
+  is set.
-   selected.
+- **Clicking empty space** shows a **"Save point..."** form (with an optional
-3. In the dialog, pick a **destination** — by clicking the map, **searching** a
+  label) to save it as a browser-local Saved Point, or the same
-   POI (local or online via Nominatim), or choosing a **Saved Point**.
+  "Directions from here" action.
-4. **Calculate route** enables once both points are set. The computation runs in
+
+From the opened **Directions** panel:
+
+1. **Origin** is already set (from "Directions from here"). Pick a
+   **destination** - by clicking another point (and choosing
+   "Directions to here"), **searching** a POI (local or online via Nominatim),
+   or choosing a **Saved Point**.
+2. **Calculate route** enables once both points are set. The computation runs in
    a **Web Worker** (off the UI thread) with a live **progress bar**.
-5. On completion the panel shows the **turn-by-turn** directions (*Head north*,
+3. On completion the panel shows the **turn-by-turn** directions (*Head north*,
-   *Turn right*, *Arrive at destination*, …) for **Drive** mode, plus distance,
+   *Turn right*, *Arrive at destination*, ...) for **Drive** mode, plus distance,
    estimated travel time, and the drawn route.
 
-Other behaviors:
-
-- **Route options** (collapsed): **avoid certain POI categories** (schools, fire
-  stations, fuel stations, parking, restaurants, …) and choose the **travel
-  mode** (Drive / Walk).
-- **Robustness:** if the origin/destination are far from the routable road
-  network, or the destination is disconnected / fully blocked by avoided
-  categories, the app reports *why* and still draws the **closest reachable**
-  portion of a route (flagged as a partial path) instead of failing silently.
-- **On-demand layer loading:** if the road-data layer needed for routing isn't
-  loaded, the dialog prompts you to load it ("Road data layer needed for route
-  computation") rather than silently disabling.
-
-Routing is done **entirely in the browser** (`src/lib/routing.ts`, invoked from
-`src/lib/routing.worker.ts`): an A*-search over the graph built from the OSM
-dump. Points are snapped to the nearest graph node. When you enable a category
-to avoid, edges within a radius of POIs in that category are heavily penalized
-(or blocked) so the route routes around them.
-
-```ts
-import { route } from '$lib/routing';
-const r = route(graph, [latA, lonB], [latB, lonB], pois, [
-  { category: 'amenity', value: 'school', radiusM: 300, block: true }
-]);
-// r.found, r.path ([[lat,lon],...]), r.distanceM
-// r.partial (best-effort partial route when the destination is unreachable),
-// r.fromSnapM / r.toSnapM (distance from A/B to nearest road),
-// r.reason (human explanation when no full route exists),
-// r.turns (turn-by-turn steps for driving mode)
-```
-
 ## Saved Points (browser-local)
 
-Clicking an empty spot on the map creates a **Saved Point** — a location you
+Clicking an empty spot on the map opens a **context dialog** with a
-want to remember. Saved points are stored only in your browser's `localStorage`
+**"Save point..."** button (plus an optional label). Saving creates a
-and shown as a toggleable **"Saved Points"** layer in the legend, with a
+**Saved Point** — a location you want to remember. Saved points are stored only
-distinct purple pin. They can be used as route origins or destinations.
+in your browser's `localStorage` and shown as a toggleable **"Saved Points"**
+layer in the legend, with a distinct purple pin. They can be used as route
+origins or destinations.
 
 Because they live only in the browser, **Export / Import** (in ⚙ Preferences)
 lets you back them up as a JSON file and restore them (merged, deduplicated by