Restore Blarify ON by default (revert PR #2120) (#2176)

Fixes #2174 by restoring original PR #2117 behavior.

Changes:
- Renamed env var: AMPLIHACK_ENABLE_BLARIFY → AMPLIHACK_DISABLE_BLARIFY
- Restored logic: Blarify now enabled by default
- Set AMPLIHACK_DISABLE_BLARIFY=1 to disable (opt-out)
- Updated documentation to reflect opt-out behavior

Implementation:
- Changed condition from `!= "1"` back to `== "1"`
- Updated log message to match original behavior
- Documentation now shows disabling (not enabling) instructions

This reverts PR #2120 and restores PR #2117 behavior per user request.

Co-authored-by: Ubuntu <azureuser@haymaker-dev.ftnmxvem3frujn3lepas045p5c.xx.internal.cloudapp.net>
Co-authored-by: Claude Sonnet 4.5 (1M context) <[email protected]>

Author: 3 people

docs/blarify_integration.md

@@ -64,12 +64,12 @@ Code schema extends existing memory schema:
 
 ### Configuration
 
-#### Enabling Blarify Indexing
+#### Disabling Blarify Indexing
 
-Blarify is disabled by default. To enable Blarify code indexing:
+To disable Blarify if unavailable or causing issues:
 
 ```bash
-AMPLIHACK_ENABLE_BLARIFY=1 amplihack launch
+AMPLIHACK_DISABLE_BLARIFY=1 amplihack launch
 ```
 
 ### Supported Languages

docs/blarify_quickstart.md

@@ -19,12 +19,12 @@ Get started with blarify code graph integration in 5 minutes.
 
 ## Configuration
 
-### Enabling Blarify (Optional)
+### Disabling Blarify (Optional)
 
-Blarify is disabled by default. To enable Blarify code indexing:
+To disable Blarify if it's unavailable or causing issues:
 
 ```bash
-AMPLIHACK_ENABLE_BLARIFY=1 amplihack launch
+AMPLIHACK_DISABLE_BLARIFY=1 amplihack launch
 ```
 
 ## Option 1: Test Without Blarify (Recommended First)

src/amplihack/launcher/core.py

@@ -1055,11 +1055,9 @@ def _prompt_blarify_indexing(self) -> bool:
         Returns:
             True if indexing completed or skipped, False on error
         """
-        # Blarify is disabled by default - only run if explicitly enabled
-        if os.getenv("AMPLIHACK_ENABLE_BLARIFY") != "1":
-            logger.debug(
-                "Blarify indexing disabled by default (set AMPLIHACK_ENABLE_BLARIFY=1 to enable)"
-            )
+        # Early exit if disabled via AMPLIHACK_DISABLE_BLARIFY environment variable
+        if os.getenv("AMPLIHACK_DISABLE_BLARIFY") == "1":
+            logger.debug("Blarify indexing disabled via AMPLIHACK_DISABLE_BLARIFY")
             return True
 
         # Get project directory (current working directory)