feat(pr): add review thread replies and resolution

README.md

@@ -78,8 +78,8 @@ keyboard alone, and the mouse stays first-class.
   lazily loaded code changes in the Local Changes-style Pierre file tree,
   switch stacked/split layout in place, jump from timeline comments to their
   file/thread, read GitHub review threads with replies directly beneath their code,
-  and add stale-head-guarded comments to selected
-  line ranges. A compact readiness ledger combines review,
+  reply to them, resolve or reopen them, and add stale-head-guarded comments to
+  selected line ranges. A compact readiness ledger combines review,
   checks, conflicts, merge state, and provider freshness before merging with
   merge-commit, squash, or rebase through a GitHub-style split control.
   Authentication stays in the signed-in `gh` / `az` CLI; provider policies

ROADMAP.md

@@ -1064,8 +1064,9 @@ passes on its measured platform. Doc-only change: PRD §8, `docs/perf-baseline.m
   rendered Markdown, color-coded checks, discussions with top-level comment
   creation, current-branch auto-open, and full-width lazy selected-file Pierre
   diffs shipped 2026-07-13 through authenticated provider CLIs. Inline/review
-  actions, Azure policies, and merge controls remain; GitLab and Bitbucket are
-  follow-on provider adapters.
+  comments plus GitHub thread replies/resolution and merge controls now ship;
+  batched review actions and richer Azure parity remain. GitLab and Bitbucket
+  are follow-on provider adapters.
 - ☐ Telemetry (opt-in, clearly disclosed)
 - ☐ Localization framework + English baseline
 - ☑ Performance pass on 100k-commit repos — closed 2026-07-06 with the 0.5
@@ -1641,6 +1642,15 @@ to local `HEAD`; it never includes unstaged drafts or creates the PR itself.
 Vendor CLI health errors remain distinct from signed-out sessions, and sign-in
 is preflighted before Strand reports that the browser or CLI flow has started.
 
+**Hosted PR thread writes shipped (2026-07-15):** GitHub review-thread cards
+now expose provider-permission-gated Reply and Resolve/Reopen actions. Writes
+use stable GraphQL thread node IDs through the signed-in `gh` CLI, with bodies
+and variables sent over stdin; the small mutation outcomes patch both the
+inline Changes card and flattened Conversation timeline locally, preserving the
+mounted Pierre diff, file selection, scroll, focus, and per-thread drafts.
+Coordinate-based new comments retain their exact-head guard; replies and thread
+state do not need one because they target an existing stable thread.
+
 ---
 
 ## 1.1+ — Post-1.0

TASKS.md

@@ -1326,9 +1326,12 @@ tree: watch the agent work, review fast, accept or reject safely.
     line-range selection, persistent fetched thread cards with replies and
     resolved/outdated state, and an annotation-row composer through
     `repo_pull_request_inline_comment`, with
-    exact-head validation before publishing. Reply creation, Azure
-    iteration-tracked inline comments, direct binary attachment uploads,
-    suggestions, and thread resolution remain.
+    exact-head validation before publishing. GitHub thread cards now publish
+    immediate replies and Resolve/Reopen writes through provider-capability-
+    gated GraphQL mutations, patching Changes + Conversation locally without a
+    detail/patch reload (`repo_pull_request_thread_reply`,
+    `repo_pull_request_thread_resolve`). Azure iteration-tracked inline writes,
+    direct binary attachment uploads, and suggestions remain.
   - ☐ Submit reviews: approve, request changes, dismiss/update a review where supported.
   - ◐ PR review ledger + merge-readiness model (see
     `docs/pull-request-improvements.md`).

crates/strand-tauri/src/commands.rs

@@ -302,6 +302,35 @@ pub async fn repo_pull_request_inline_comment(
     .await
 }
 
+/// Reply to an existing provider review thread. The provider thread ID is a
+/// stable target, so this write does not depend on diff coordinates or head SHA.
+#[tauri::command(async)]
+pub async fn repo_pull_request_thread_reply(
+    path: String,
+    thread_id: String,
+    body: String,
+) -> CmdResult<pull_requests::PullRequestComment> {
+    run_blocking("pull request thread reply", move || {
+        pull_requests::reply_to_thread(&path, &thread_id, &body)
+            .map_err(|message| CmdError { message })
+    })
+    .await
+}
+
+/// Resolve or reopen an existing provider review thread.
+#[tauri::command(async)]
+pub async fn repo_pull_request_thread_resolve(
+    path: String,
+    thread_id: String,
+    resolved: bool,
+) -> CmdResult<pull_requests::PullRequestReviewThreadUpdate> {
+    run_blocking("pull request thread resolution", move || {
+        pull_requests::set_thread_resolved(&path, &thread_id, resolved)
+            .map_err(|message| CmdError { message })
+    })
+    .await
+}
+
 /// Merge a hosted pull request through its provider. The expected source
 /// commit prevents merging unseen updates; provider policies remain enforced.
 #[tauri::command(async)]

crates/strand-tauri/src/main.rs

@@ -85,6 +85,8 @@ fn main() {
             commands::repo_pull_request_diff,
             commands::repo_pull_request_comment,
             commands::repo_pull_request_inline_comment,
+            commands::repo_pull_request_thread_reply,
+            commands::repo_pull_request_thread_resolve,
             commands::repo_pull_request_merge,
             commands::repo_diff_unstaged,
             commands::repo_diff_staged,