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>

gateway/stream_consumer.py

@@ -68,6 +68,7 @@ class GatewayStreamConsumer:
         self._already_sent = False
         self._edit_supported = True  # Disabled on first edit failure (Signal/Email/HA)
         self._last_edit_time = 0.0
+        self._last_sent_text = ""   # Track last-sent text to skip redundant edits
 
     @property
     def already_sent(self) -> bool:
@@ -141,6 +142,9 @@ class GatewayStreamConsumer:
         try:
             if self._message_id is not None:
                 if self._edit_supported:
+                    # Skip if text is identical to what we last sent
+                    if text == self._last_sent_text:
+                        return
                     # Edit existing message
                     result = await self.adapter.edit_message(
                         chat_id=self.chat_id,
@@ -149,6 +153,7 @@ class GatewayStreamConsumer:
                     )
                     if result.success:
                         self._already_sent = True
+                        self._last_sent_text = text
                     else:
                         # Edit not supported by this adapter — stop streaming,
                         # let the normal send path handle the final response.
@@ -170,6 +175,7 @@ class GatewayStreamConsumer:
                 if result.success and result.message_id:
                     self._message_id = result.message_id
                     self._already_sent = True
+                    self._last_sent_text = text
                 else:
                     # Initial send failed — disable streaming for this session
                     self._edit_supported = False