fix(pr-management-triage): suppress already-acted-on PRs with unchanged head SHA

plugins/magpie-pr-management/skills/pr-triage/SKILL.md

@@ -27,7 +27,7 @@ argument-hint: "[pr:N] [label:LBL] [author:LOGIN] [review-for-me] [stale] [repo:
 capability: capability:triage
 surface_hash: sha256:5c92df54aab39ad7
 license: Apache-2.0
-measured_tokens: 5005
+measured_tokens: 5027
 ---
 <!-- SPDX-License-Identifier: Apache-2.0
      https://www.apache.org/licenses/LICENSE-2.0 -->
@@ -316,7 +316,7 @@ Selector semantics (`triage pr:<N>` / `label:<LBL>` / `author:<LOGIN>` / `review
 ---
 **Step 0.7 — backport check:** only when `backport_branches` is configured — for every open PR targeting a release branch (any author, drafts included), verify it is a direct cherry-pick of a default-branch commit and, under `backport_policy: fixes-only`, that the source change is a fix rather than a feature, behaviour change, deprecation, removal or refactor; the spec is in [`backport-check.md`](backport-check.md).
 
-**Step 1 — fetch:** resolve the selector per [`fetch-and-batch.md#inputs`](fetch-and-batch.md#inputs), walk every page of the aliased PR-list query until `pageInfo.hasNextPage` is false, deduplicate at the end, and prefetch the `action_required` run index and the recent main-branch failures once per session — the canonical loop is in [`fetch-and-batch.md#full-pagination-loop`](fetch-and-batch.md#full-pagination-loop).
+**Step 1 — fetch:** resolve the selector per [`fetch-and-batch.md#inputs`](fetch-and-batch.md#inputs), walk every page of the aliased PR-list query until `pageInfo.hasNextPage` is false, deduplicate at the end, silently suppress PRs the session cache already holds under a terminal `action_taken` with an unchanged head SHA, and prefetch the `action_required` run index and the recent main-branch failures once per session — the canonical loop is in [`fetch-and-batch.md#full-pagination-loop`](fetch-and-batch.md#full-pagination-loop).
 
 **Step 2 — classify:** run **every PR fetched in Step 1** through
 [`classify-and-act.md`](classify-and-act.md), once — the pre-filters

plugins/magpie-pr-management/skills/pr-triage/fetch-and-batch.md

@@ -326,7 +326,10 @@ returns, for every PR on the page:
 
 Accumulate every PR into a single in-memory list, then deduplicate
 it by number after the final page, keeping each PR's last (freshest)
-occurrence. Do not classify, do not present, do not prompt the
+occurrence, then silently suppress PRs the session cache already
+holds under a terminal `action_taken` with an unchanged head SHA (see
+[`#full-pagination-loop`](#full-pagination-loop)). Do not classify,
+do not present, do not prompt the
 maintainer between pages — the fetch loop is uninterrupted,
 runs to completion, and emits one progress line per page so
 the maintainer can step away during the wait. See
@@ -355,6 +358,8 @@ loop serially until `pageInfo.hasNextPage` is false, then hand
 the accumulated list to Step 2.
 
 ```text
+cache = load_session_cache().prs        # may be empty — a fresh session starts empty
+
 all_prs = []
 cursor = null
 page = 1
@@ -374,7 +379,18 @@ for pr in reverse(all_prs):
         continue
     seen_numbers.add(pr.number)
     deduped_prs_reversed.append(pr)
-return reverse(deduped_prs_reversed)
+queue = reverse(deduped_prs_reversed)
+
+# Session suppression: a PR already taken to a terminal action earlier
+# in this session, whose head SHA is unchanged, has nothing new to
+# read. Drop it silently — no queue entry, no progress line, no prompt.
+kept = []
+for pr in queue:
+    entry = cache.get(pr.number)
+    if entry and entry.get("action_taken") and entry.get("head_sha") == pr.head_sha:
+        continue
+    kept.append(pr)
+return kept
 ```
 
 Key invariants:
@@ -398,6 +414,19 @@ Key invariants:
   first record for each PR number, then restore the list order.
   This keeps the last (freshest) occurrence and its position in
   the fetched ordering. Leave an already-unique list unchanged.
+- **Suppress already-acted-on, unchanged-head entries.** After
+  deduplication, drop every PR the session cache holds under a
+  terminal `action_taken` whose cached `head_sha` equals the
+  freshly fetched head SHA — the decision was already made and
+  nothing has changed since, so re-surfacing the PR only invites
+  a second, possibly different decision. The drop is silent: the
+  PR must not appear in any group, progress line, or the Step 6
+  summary. A PR whose head SHA **differs** does not match the
+  suppression and is re-classified as usual — the invalidation
+  rule in [`#session-cache`](#session-cache) and this suppression
+  are complementary, not conflicting. The suppression is session
+  state: it dies with the cache, so a fresh session re-surfaces
+  everything.
 - **Skip prefetch heuristics.** With pages fetched serially up
   front, there is no per-page maintainer wait to overlap with
   a next-page prefetch — the old prefetch-during-interaction
@@ -686,6 +715,15 @@ anything that isn't needed. Schema:
 - An entry's `head_sha` must match the head SHA returned by the
   current fetch — if it doesn't, the contributor pushed since
   and the entry is stale. Drop it and re-classify.
+- Conversely, an entry carrying a terminal `action_taken` whose
+  `head_sha` **does** match the current fetch suppresses the PR
+  for the rest of the session: Step 1 drops it silently before
+  handing the queue to Step 2 (see
+  [`#full-pagination-loop`](#full-pagination-loop)). Unchanged
+  head plus already-acted-on means nothing new to read; a changed
+  head falls through to the staleness rule above, so the two
+  rules never fire against each other. The suppression dies with
+  the session cache — a fresh session re-surfaces everything.
 - The `recent_main_failures` block is valid for 4 hours; after
   that, re-fetch via the canary/main-branch failure query
   (see below).

tools/skill-evals/README.md

@@ -33,7 +33,7 @@ Suites are currently implemented for:
 - **pr-management-code-review**: 126 cases across 28 suites (selector-resolution, step-1-selectors-match-chips, step-2-reviewer-resolution, step-2.5-slop-detection, step-3-security-disclosure-scan, step-3-ai-authorship-disclosure, step-4-* checks, step-5-adversarial-integration, step-6-disposition, step-7b-review-body-attribution, review-risk-classify, injection-guard, review-disposition, review-handoff)
 - **pr-management-mentor** — 29 cases across 3 steps (tone-checks, hand-off)
 - **pr-management-stats** — 13 cases across 2 steps (classify, pressure-weight)
-- **pr-management-triage** — 59 cases across 6 steps (backport-check, pre-filter, decision-table, terminal-links, pagination-dedup, interaction-progress)
+- **pr-management-triage** — 62 cases across 6 steps (backport-check, pre-filter, decision-table, terminal-links, pagination-dedup, interaction-progress)
 - **list-skills** — 8 cases across 2 steps (step-1-command, step-2-present)
 - **setup-isolated-setup-verify** — 17 cases across 3 steps (runtime-routing, step-1-classify, step-2-recommend)
 - **setup-isolated-setup-update** — 15 cases across 4 steps (runtime-routing, step-snapshot-drift, step-tool-freshness, step-after-report)

tools/skill-evals/evals/pr-management-triage/README.md

@@ -5,15 +5,15 @@
 
 Behavioral evals for the `pr-management-triage` skill.
 
-## Suites (59 cases total)
+## Suites (62 cases total)
 
 | Suite | Step | Cases | What it covers |
 |---|---|---|---|
 | backport-check | Step 0.7 (backport check) | 5 | Direct cherry-pick of a fix→hand-off, hand-adapted backport (`-U0` patch-id mismatch)→surface, faithful cherry-pick of a behaviour change/deprecation→close under `fixes-only`, every commit already on the base→close, no resolvable source commit→surface |
 | pre-filter | Step 2 (pre-filters) | 21 | F1 (collaborator), F2 (bot), F3 (draft recent), F4 (already ready), F5a (active maintainer feedback — general comments, review-thread comments, **and submitted top-level reviews with a non-empty body**, including the 72-hour and last-commit boundaries), F5b (maintainer ping unanswered; a ping answered by a review does not fire), F6 (maintainer co-drafted), row-6 (viewer is author), row-7a (fresh PR); clean contributor continues |
 | decision-table | Step 2 (decision table) | 22 | Rows 3/4 (already-triaged via a cross-triager comment marker→skip, via body-fold block→skip, and via a fold carrying `by=<another triager>`→skip with the reason naming that triager), plus the negative case (a non-triager comment quoting the QC link is not a marker), 7b (security signal), 9 (conflict→draft), 10 (all systemic→rerun), 11 (partial systemic→rerun), 12 (static-only→comment), 13 (flaky ≤2→rerun), 14a (author confirmed→mark-ready), 14b (pending confirmation→skip), 14c (threads addressed→request-author-confirmation), 15 (threads→ping), 16 (no CI→rebase), 18 (changes-requested+new-commits→ping), 19 (already ready→skip), 20 (passing→mark-ready), 21 (stale draft sweep→close), 22 (rollup anomaly→skip) |
 | terminal-links | Golden rule 10 | 5 | Short, context-short, and full PR references retain their visible form and use the canonical target; `NO_COLOR` (including an empty value) and `TERM=dumb` select the plain-text fallback |
-| pagination-dedup | Step 1 (full pagination) | 2 | A PR that moves to a later page is emitted once at its freshest occurrence; distinct PRs keep their fetched order |
+| pagination-dedup | Step 1 (full pagination) | 5 | A PR that moves to a later page is emitted once at its freshest occurrence; distinct PRs keep their fetched order; a PR already acted on earlier in the session is silently suppressed while its head SHA is unchanged, re-classified once it moved, and never suppressed from a cache entry that carries no terminal `action_taken` |
 | interaction-progress | Interaction loop | 4 | Per-PR drill-ins retain the original one-based group position at the first, middle, and last rows and show the active classify-to-propose transition for `[E]` and `[P]` entry |
 
 The two body-fold cases (`case-17-fold-already-triaged`,

tools/skill-evals/evals/pr-management-triage/pagination-dedup/fixtures/case-3-acted-unchanged-head-suppressed/expected.json

@@ -0,0 +1,5 @@
+{
+  "prs": [
+    {"number": 42, "updatedAt": "2026-08-05T12:05:00Z", "headRefOid": "head-42"}
+  ]
+}

tools/skill-evals/evals/pr-management-triage/pagination-dedup/fixtures/case-3-acted-unchanged-head-suppressed/report.md

@@ -0,0 +1,31 @@
+<!-- SPDX-License-Identifier: Apache-2.0
+     https://www.apache.org/licenses/LICENSE-2.0 -->
+
+The search is sorted by `updated-asc`. These pages were fetched serially:
+
+Page 1:
+
+```json
+[
+  {"number": 41, "updatedAt": "2026-08-05T12:00:00Z", "headRefOid": "head-41"},
+  {"number": 42, "updatedAt": "2026-08-05T12:05:00Z", "headRefOid": "head-42"}
+]
+```
+
+Page 1 reports `hasNextPage: false`.
+
+The session cache for this repository holds:
+
+```json
+{
+  "prs": {
+    "41": {
+      "head_sha": "head-41",
+      "classification": "deterministic_flag",
+      "suggested_action": "comment",
+      "action_taken": "comment",
+      "action_at": "2026-08-05T09:30:00Z"
+    }
+  }
+}
+```

tools/skill-evals/evals/pr-management-triage/pagination-dedup/fixtures/case-4-acted-pushed-head-reclassified/expected.json

@@ -0,0 +1,6 @@
+{
+  "prs": [
+    {"number": 51, "updatedAt": "2026-08-05T12:10:00Z", "headRefOid": "fresh-51"},
+    {"number": 52, "updatedAt": "2026-08-05T12:15:00Z", "headRefOid": "head-52"}
+  ]
+}

tools/skill-evals/evals/pr-management-triage/pagination-dedup/fixtures/case-4-acted-pushed-head-reclassified/report.md

@@ -0,0 +1,33 @@
+<!-- SPDX-License-Identifier: Apache-2.0
+     https://www.apache.org/licenses/LICENSE-2.0 -->
+
+The search is sorted by `updated-asc`. These pages were fetched serially:
+
+Page 1:
+
+```json
+[
+  {"number": 51, "updatedAt": "2026-08-05T12:10:00Z", "headRefOid": "fresh-51"},
+  {"number": 52, "updatedAt": "2026-08-05T12:15:00Z", "headRefOid": "head-52"}
+]
+```
+
+Page 1 reports `hasNextPage: false`. PR 51 was acted on earlier in this
+session, but its head SHA differs from the cached one — the contributor
+pushed since.
+
+The session cache for this repository holds:
+
+```json
+{
+  "prs": {
+    "51": {
+      "head_sha": "old-51",
+      "classification": "deterministic_flag",
+      "suggested_action": "rebase",
+      "action_taken": "rebase",
+      "action_at": "2026-08-05T09:45:00Z"
+    }
+  }
+}
+```

tools/skill-evals/evals/pr-management-triage/pagination-dedup/fixtures/case-5-classified-without-action-stays/expected.json

@@ -0,0 +1,6 @@
+{
+  "prs": [
+    {"number": 61, "updatedAt": "2026-08-05T12:20:00Z", "headRefOid": "head-61"},
+    {"number": 62, "updatedAt": "2026-08-05T12:25:00Z", "headRefOid": "head-62"}
+  ]
+}

tools/skill-evals/evals/pr-management-triage/pagination-dedup/fixtures/case-5-classified-without-action-stays/report.md

@@ -0,0 +1,31 @@
+<!-- SPDX-License-Identifier: Apache-2.0
+     https://www.apache.org/licenses/LICENSE-2.0 -->
+
+The search is sorted by `updated-asc`. These pages were fetched serially:
+
+Page 1:
+
+```json
+[
+  {"number": 61, "updatedAt": "2026-08-05T12:20:00Z", "headRefOid": "head-61"},
+  {"number": 62, "updatedAt": "2026-08-05T12:25:00Z", "headRefOid": "head-62"}
+]
+```
+
+Page 1 reports `hasNextPage: false`. PR 61 was classified earlier in this
+session but no action was taken on it — the cache entry has no terminal
+`action_taken`.
+
+The session cache for this repository holds:
+
+```json
+{
+  "prs": {
+    "61": {
+      "head_sha": "head-61",
+      "classification": "deterministic_flag",
+      "suggested_action": "draft"
+    }
+  }
+}
+```