README: update for credentials-file config and recent GUI changes

- Credentials file is now the single source for vin, interval_s, host,
  port, log_dir; document new format with nested credentials block
- CLI reference trimmed to the remaining flags only
- Push server section: 24 h rolling window instead of same-day history
- GUI section: connection persistence, clear-on-reconnect, per-plot time
  window spinner, x-axis fit when data < window size

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

README.md

@@ -16,6 +16,7 @@ server/
   storage_helpers.py— load / save JSON store, midnight rotation helpers
   we_connect.py     — WeConnect login and vehicle selection
   log_config.py     — logging setup
+credentials/        — JSON config files (gitignored)
 requirements.txt
 ```
 
@@ -25,67 +26,89 @@ requirements.txt
 pip install weconnect PyQt5 pyqtgraph
 ```
 
+Or use the installer which also sets up a systemd user service:
+
+```bash
+./install.sh
+```
+
 ## Collector (`collect.py`)
 
 Connects to WeConnect, polls selected domains at a configurable interval, and
-appends records to a JSON file.  Simultaneously runs a TCP push server so
+appends records to a rotating JSON log.  Simultaneously runs a TCP push server
-clients receive every new snapshot the moment it is collected.
+so clients receive every new snapshot the moment it is collected.
 
 ### Quick start
 
 ```bash
-# Credentials via environment variables, all defaults
+python collect.py -c credentials/my_car.json
-export WC_USER=me@example.com
-export WC_PASS=secret
-python collect.py
-
-# Credentials from a JSON file, 10-minute interval
-python collect.py -c credentials/my_car.json -i 600
 ```
 
-### Credentials file (`-c FILE`)
+Username and password can also be supplied via environment variables
+(override the credentials file):
+
+```bash
+export WC_USER=me@example.com
+export WC_PASS=secret
+python collect.py -c credentials/my_car.json
+```
+
+### Credentials file
+
+All connection and collection settings live in a single JSON file:
 
 ```json
 {
-  "username": "me@example.com",
+  "credentials": {
-  "password": "secret",
+    "username": "me@example.com",
-  "vin":      "WVWZZZE1ZMP000000",
+    "password": "secret"
-  "domains":  ["charging", "measurements", "readiness"]
+  },
+  "vin":        "WVWZZZE1ZMP000000",
+  "domains":    ["charging", "measurements", "readiness"],
+  "interval_s": 300,
+  "host":       "0.0.0.0",
+  "port":       9999,
+  "log_dir":    "./logs"
 }
 ```
 
-All keys are optional; explicit CLI flags and `WC_USER` / `WC_PASS`
+| Key | Default | Description |
-environment variables take precedence.
+|-----|---------|-------------|
+| `credentials.username` | — | WeConnect / MyVolkswagen email |
+| `credentials.password` | — | WeConnect password |
+| `vin` | first vehicle | Target VIN |
+| `domains` | `["charging","measurements","readiness"]` | Domains to collect (list or `"all"`) |
+| `interval_s` | `300` | Collection interval in seconds |
+| `host` | `"0.0.0.0"` | Push server bind address |
+| `port` | `9999` | Push server TCP port |
+| `log_dir` | `"./logs"` | Directory for rotating JSON log files |
 
 ### CLI reference
 
-| Flag | Default | Description |
+Only a handful of flags remain; all vehicle/server settings are in the credentials file.
-|------|---------|-------------|
+
-| `-c FILE` | — | JSON credentials file |
+| Flag | Description |
-| `-u / -p` | `WC_USER` / `WC_PASS` | Username / password |
+|------|-------------|
-| `--vin` | first vehicle | Target VIN |
+| `-c FILE` | Credentials / settings file (required) |
-| `-d DOMAINS` | `charging,measurements,readiness` | Comma-separated domains or `all` |
+| `-u / -p` | Override username / password (also `WC_USER` / `WC_PASS`) |
-| `-i SECONDS` | `300` | Collection interval |
+| `-d DOMAINS` | Override domains (comma-separated or `all`) |
-| `-o FILE` | `logs/YYYY_MM_DD_HH_MM_SS_<VIN>.json` | Output file |
+| `--max-records N` | Keep only the last N records per file |
-| `--max-records N` | unlimited | Keep only last N records |
+| `-v` | Verbose / debug logging |
-| `--host` | `0.0.0.0` | Push server bind address |
+| `--list-domains` | Print available domains and exit |
-| `--port` | `9999` | Push server TCP port |
-| `-v` | — | Verbose / debug logging |
-| `--list-domains` | — | Print available domains and exit |
 
 **Available domains:** `charging`, `climatisation`, `measurements`,
 `readiness`, `parking`, `access`
 
 ### Log rotation
 
-When using the default `logs/` directory the collector automatically starts a
+A new file is started automatically after midnight UTC; previous files are kept
-new file after midnight UTC, keeping all previous files intact.  On startup the
+intact.  On startup and on each new client connection the collector sends the
-full day's records are pre-loaded from disk so newly connected clients receive
+last 24 hours of records, so clients always receive a full rolling window
-the complete history.
+regardless of when midnight falls.
 
 ### Output format
 
-Each file is a JSON object:
+Log files are named `YYYY_MM_DD_HH_MM_SS_<VIN>.json` and contain:
 
 ```json
 {
@@ -95,7 +118,7 @@ Each file is a JSON object:
       "ts": "2025-05-25T10:00:00+00:00",
       "charging": {
         "batteryStatus": {
-          "currentSOC":          { "value": 80, "unit": "%" },
+          "currentSOC":            { "value": 80,  "unit": "%" },
           "cruisingRangeElectric": { "value": 310, "unit": "km" }
         }
       }
@@ -108,26 +131,26 @@ Physical values are always `{"value": …, "unit": …}` objects.
 
 ## Push server protocol
 
-The server listens on `--host`:`--port` (default `0.0.0.0:9999`).
+The server listens on the `host`:`port` from the credentials file (default `0.0.0.0:9999`).
 
-* On connect: sends all records from the current day, sorted by timestamp.
+* On connect: sends all records from the last 24 hours, sorted by timestamp.
 * On each new poll: sends the new snapshot immediately.
 
-All messages are **newline-delimited JSON** (one record per line, `\n`
+All messages are **newline-delimited JSON** (one record per line, `\n` terminated).
-terminated).
 
 ## GUI client (`gui_client.py`)
 
 ```bash
 python gui_client.py
-python gui_client.py --host 192.168.1.10 --port 9999
 ```
 
-Dark theme matching nmea_client.  Three tabs:
+Dark theme. Three tabs:
 
 ### Connector tab
 
-Host / port fields, Connect / Disconnect button, and connection status.
+Enter host and port, then click **Connect**.  Settings are saved automatically
+and restored on the next launch.  All plot data is cleared on each
+connect so fresh server history is never mixed with stale local data.
 
 ### Dashboard tab
 
@@ -138,21 +161,20 @@ showing value and unit.  Expand state is preserved across updates.
 
 8 plots (4 × 2) in a scrollable grid.  Each plot has its own control bar:
 
+* **Time window spinner** — show the last 1–24 hours (per plot).
 * **Dropdown + `+`** — select a signal and add it as a trace (max 4 per plot).
 * **Colored chips (`name ×`)** — click to remove a trace.
 * Zoom / pan with mouse; crosshair cursor tracks mouse position.
+* When available data is less than the selected window, the x-axis adjusts
+  to the actual data extent — no empty gap on the left.
 
-Trace selections are persisted to
+Trace selections, time windows, and connection settings are persisted to
 `~/.config/we_monitor/plot_settings.json` and restored automatically on
-the next launch once matching signals arrive.
+the next launch.
-
-Signal labels use short human-readable names (e.g. *SOC*, *range*,
-*outside temp*) defined in `_TRACE_LABELS` near the top of `gui_client.py`.
 
 ## CLI test client (`client.py`)
 
 ```bash
-python client.py
 python client.py --host 192.168.1.10 --port 9999
 ```