Raise convo_miner MAX_FILE_SIZE cap 10 MB → 500 MB

Mirrors the miner.py fix in this same branch. convo_miner.py had the
exact same 10 MB cap at line 58 that silently dropped long transcripts
via continue. Long Claude Code sessions, multi-year ChatGPT exports,
and lifetime Slack dumps all exceed 10 MB. Same silent-drop pattern,
different file.

Raised to 500 MB to match miner.py for consistency; downstream chunking
means source file size does not affect storage or embedding cost.

Tests: tests/test_convo_miner_size_cap.py (1 test)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

mempalace/convo_miner.py

@@ -55,7 +55,11 @@ CONVO_EXTENSIONS = {
 
 MIN_CHUNK_SIZE = 30
 CHUNK_SIZE = 800  # chars per drawer — align with miner.py
-MAX_FILE_SIZE = 10 * 1024 * 1024  # 10 MB — skip files larger than this
+MAX_FILE_SIZE = 500 * 1024 * 1024  # 500 MB — skip files larger than this.
+# Matches miner.py at 500 MB. Long Claude Code sessions, multi-year
+# ChatGPT exports, and lifetime Slack dumps routinely exceed 10 MB; the
+# cap at that level silently dropped them with `continue`. Source size
+# does not affect storage or embedding cost — chunking happens downstream.
 
 
 def _register_file(collection, source_file: str, wing: str, agent: str):

tests/test_convo_miner_size_cap.py

@@ -0,0 +1,31 @@
+"""TDD: convo_miner.py must not silently drop transcripts larger than 10 MB.
+
+Mirrors the miner.py fix shipped in the same PR family (see
+test_miner_jsonl_visibility.py). Long Claude Code sessions, ChatGPT
+exports, and multi-year Slack dumps routinely exceed 10 MB. The cap
+silently `continue`s past them at convo_miner.py:~289, same silent-drop
+pattern as the project miner's.
+
+Written BEFORE the fix.
+"""
+
+from mempalace.convo_miner import MAX_FILE_SIZE
+
+
+class TestConvoMinerSizeCap:
+    def test_max_file_size_accommodates_long_transcripts(self):
+        """The cap must be well above any realistic transcript.
+
+        Long sessions and lifetime exports exceed 10 MB. The cap exists
+        as a sanity rail against pathological binaries, not as a limit
+        on legitimate text — downstream chunking means source size does
+        not matter for storage or embedding cost.
+        """
+        assert MAX_FILE_SIZE >= 100 * 1024 * 1024, (
+            f"convo_miner.MAX_FILE_SIZE is {MAX_FILE_SIZE} bytes "
+            f"({MAX_FILE_SIZE / 1024 / 1024:.0f} MB). Same silent-drop "
+            "bug as miner.py's old 10 MB cap — long transcripts get "
+            "filtered out at convo_miner.py:~289 with `continue`. "
+            "Raise to at least 100 MB (match miner.py at 500 MB for "
+            "consistency across both miners)."
+        )