fix: Telegram streaming — config bridge, not-modified, flood control (#1782)

* fix: NameError in OpenCode provider setup (prompt_text -> prompt)

The OpenCode Zen and OpenCode Go setup sections used prompt_text()
which is undefined. All other providers correctly use the local
prompt() function defined in setup.py. Fixes crash during
'hermes setup' when selecting either OpenCode provider.

* fix: Telegram streaming — config bridge, not-modified, flood control

Three fixes for gateway streaming:

1. Bridge streaming config from config.yaml into gateway runtime.
   load_gateway_config() now reads the 'streaming' key from config.yaml
   (same pattern as session_reset, stt, etc.), matching the docs.
   Previously only gateway.json was read.

2. Handle 'Message is not modified' in Telegram edit_message().
   This Telegram API error fires when editing with identical content —
   a no-op, not a real failure. Previously it returned success=False
   which made the stream consumer disable streaming entirely.

3. Handle RetryAfter / flood control in Telegram edit_message().
   Fast providers can hit Telegram rate limits during streaming.
   Now waits the requested retry_after duration and retries once,
   instead of treating it as a fatal edit failure.

Also fixed double-edit on stream finish: the consumer now tracks
last-sent text and skips redundant edits, preventing the not-modified
error at the source.

* refactor: make config.yaml the primary gateway config source

Eliminates the per-key bridge pattern in load_gateway_config().
Previously gateway.json was the primary source and each config.yaml
key needed an individual bridge — easy to forget (streaming was
missing, causing garl4546's bug).

Now config.yaml is read first and its keys are mapped directly into
the GatewayConfig.from_dict() schema. gateway.json is kept as a
legacy fallback layer (loaded first, then overwritten by config.yaml
keys). If gateway.json exists, a log message suggests migrating.

Also:
- Removed dead save_gateway_config() (never called anywhere)
- Updated CLI help text and send_message error to reference
  config.yaml instead of gateway.json

---------

Co-authored-by: Test <test@test.com>

cli.py

@@ -3271,7 +3271,7 @@ class HermesCLI:
             print("  To start the gateway:")
             print("    python cli.py --gateway")
             print()
-            print("  Configuration file: ~/.hermes/gateway.json")
+            print("  Configuration file: ~/.hermes/config.yaml")
             print()
             
         except Exception as e:
@@ -3281,7 +3281,7 @@ class HermesCLI:
             print("    1. Set environment variables:")
             print("       TELEGRAM_BOT_TOKEN=your_token")
             print("       DISCORD_BOT_TOKEN=your_token")
-            print("    2. Or create ~/.hermes/gateway.json")
+            print("    2. Or configure settings in ~/.hermes/config.yaml")
             print()
     
     def process_command(self, command: str) -> bool: