fix(claude_code): drop the compaction summary from Common

CHANGELOG.md

@@ -13,6 +13,7 @@ Each release is published to [crates.io](https://crates.io/crates/txcript),
 
 ### Fixed
 
+- Drop the compaction summary from `claude_code` conversions ([#100](https://github.com/skillsynchq/txcript/issues/100)). The `user` line flagged `isCompactSummary` used to become a user prompt that repeated, condensed, the earlier history the file still holds before the `compact_boundary`. It now stays in the native body only.
 - Resolve a session id that exists in several stores to the most recently modified copy. `view`, `export`, `continue` and `crop` used to load whichever copy the file system listed first; discovery now breaks start-time ties by file mtime.
 
 ### Added

docs/formats/claude-code.md

@@ -60,6 +60,7 @@ everything else is preserved verbatim so a native load/save round-trips byte-los
 | `<command-name>` markup | Slash command the user ran, as XML-ish tags filling a body | `Block::ToolUse` with `Tool::Command` |
 | `<local-command-stdout>` markup | What the command printed | `Block::ToolResult` paired via `parentUuid` |
 | `<local-command-caveat>` markup | Fixed boilerplate, regenerated by the CLI | dropped |
+| `user` line with `isCompactSummary` | The summary a compaction writes after its `compact_boundary` (with `isVisibleInTranscriptOnly`); the file still holds the history it condenses, before the boundary | kept in the native body, no Common turn |
 | `summary` line | Session title with a `leafUuid` anchor | `Meta.title` (lowest precedence) |
 | `custom-title` / `agent-name` line | User-set or agent-derived title | `Meta.title` (custom-title wins) |
 | `teamName` / `agentName` envelope fields | Present on every line of a teammate session the team feature starts (distinct from the `agent-name` *line type* above) | `Meta.lineage` — see Lineage |

src/harness/claude_code.rs

@@ -181,6 +181,9 @@ pub(crate) fn records_to_messages(records: &[Record], fallback_ts: DateTime<Utc>
 
     for record in records {
         let (role, entry) = match record {
+            // The file still holds the history a compaction summary condenses
+            // (#100).
+            Record::User(e) if is_compact_summary(e) => continue,
             Record::User(e) => (Role::User, e),
             Record::Assistant(e) => (Role::Assistant, e),
             // Newer CLI versions write the same command envelopes on
@@ -224,6 +227,14 @@ pub(crate) fn records_to_messages(records: &[Record], fallback_ts: DateTime<Utc>
     messages
 }
 
+/// Whether a `user` line is the summary a compaction writes after its
+/// `compact_boundary`. Reading in file order already carries the history it
+/// condenses, which the file keeps before the boundary, so the summary would
+/// repeat it as a user turn.
+fn is_compact_summary(entry: &EntryLine) -> bool {
+    entry.extra.get("isCompactSummary") == Some(&Value::Bool(true))
+}
+
 /// The native records for a canonical conversation: one entry line per
 /// message (local-command turns as their envelopes), a linear `parentUuid`
 /// chain, and a leading summary line when `meta.title` is set. `meta.id` is

tests/integration/claude_code.rs

@@ -702,3 +702,26 @@ fn discover_leaves_lineage_none_when_the_lead_prefix_is_ambiguous() {
     let teammate = found.iter().find(|d| d.meta.id == "teammate").unwrap();
     assert!(teammate.meta.lineage.is_none());
 }
+
+/// The compaction summary repeats history the file still holds before its
+/// `compact_boundary`: it is not a user turn (#100).
+#[test]
+fn the_compaction_summary_is_not_a_user_turn() {
+    let jsonl = r#"{"type":"user","uuid":"u1","sessionId":"s","timestamp":"2026-01-02T03:04:05.000Z","message":{"role":"user","content":"first prompt"}}
+{"type":"system","subtype":"compact_boundary","uuid":"b1","parentUuid":null,"logicalParentUuid":"u1","sessionId":"s","timestamp":"2026-01-02T03:04:06.000Z","content":"Conversation compacted"}
+{"type":"user","uuid":"c1","parentUuid":"b1","isCompactSummary":true,"isVisibleInTranscriptOnly":true,"sessionId":"s","timestamp":"2026-01-02T03:04:07.000Z","message":{"role":"user","content":"summary"}}
+{"type":"user","uuid":"u2","parentUuid":"c1","sessionId":"s","timestamp":"2026-01-02T03:04:08.000Z","message":{"role":"user","content":"second prompt"}}
+"#;
+    let native = claude_code::ClaudeCode::from_text(jsonl).unwrap();
+    let conversation = claude_code::ClaudeCode::to_common(&native).unwrap();
+    let texts: Vec<&str> = conversation
+        .body
+        .iter()
+        .flat_map(|m| &m.content)
+        .filter_map(|b| match b {
+            common::Block::Text { text } => Some(text.as_str()),
+            _ => None,
+        })
+        .collect();
+    assert_eq!(texts, ["first prompt", "second prompt"]);
+}