[docs](trx-rs): update docs and split example configs

Replace trx-rs.toml.example with separate trx-server.toml.example
and trx-client.toml.example. Update OVERVIEW.md and README.md
references from trx-bin to trx-server/trx-client.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: Stanislaw Grams <stanislawgrams@gmail.com>

trx-rs.toml.example

@@ -1,79 +0,0 @@
-# trx-rs Configuration File
-#
-# Copy this file to one of:
-#   ./trx-rs.toml                    (current directory)
-#   ~/.config/trx-rs/config.toml     (user config)
-#   /etc/trx-rs/config.toml          (system-wide)
-#
-# Or specify a custom path with: trx-bin --config /path/to/config.toml
-#
-# CLI arguments override config file values.
-
-[general]
-# Callsign or station identifier displayed in frontends
-callsign = "N0CALL"
-
-# Log level: trace, debug, info, warn, error
-# log_level = "info"
-
-[rig]
-# Rig model: ft817 (more models coming)
-model = "ft817"
-# Initial frequency (Hz) before first CAT read
-initial_freq_hz = 144300000
-# Initial mode before first CAT read (LSB, USB, CW, CWR, AM, WFM, FM, DIG, PKT)
-initial_mode = "USB"
-
-[rig.access]
-# Access type: "serial" or "tcp"
-type = "serial"
-
-# Serial port settings (when type = "serial")
-port = "/dev/ttyUSB0"
-baud = 9600
-
-# TCP settings (when type = "tcp")
-# host = "192.168.1.100"
-# tcp_port = 4532
-
-[frontends.http]
-# Enable HTTP/REST frontend with SSE for real-time updates
-enabled = true
-listen = "127.0.0.1"
-port = 8080
-
-[frontends.rigctl]
-# Enable rigctl-compatible TCP interface (hamlib compatible)
-enabled = false
-listen = "127.0.0.1"
-port = 4532
-
-[frontends.http_json]
-# Enable JSON-over-TCP control interface
-enabled = true
-listen = "127.0.0.1"
-# Set to 0 to bind an ephemeral port
-port = 0
-# List of accepted bearer tokens (empty = no auth)
-# auth.tokens = ["example-token"]
-
-[frontends.qt]
-# Enable Qt/QML GUI frontend (Linux only, requires system Qt6)
-enabled = false
-# Use remote JSON TCP server instead of local rig task
-# remote.enabled = true
-# remote.url = "127.0.0.1:9000"
-# remote.auth.token = "example-token"
-
-[behavior]
-# Polling interval when idle (milliseconds)
-poll_interval_ms = 500
-
-# Polling interval when transmitting (milliseconds)
-poll_interval_tx_ms = 100
-
-# Maximum retry attempts for transient errors
-max_retries = 3
-
-# Base delay for exponential backoff (milliseconds)
-retry_base_delay_ms = 100