fix(triage-intake): guard personal-gmail sweeps against the Gmail 100-cap

The google-docs MCP listMessages tool caps at maxResults=100 and exposes no pageToken, so an unread pile over 100 truncates silently and every later anchored sweep skips the tail below the cap. That's how a 300+ backlog built up unseen by 2026-07-08. Two Scan-section rules close it: when a scan returns exactly 100, walk the tail in date slices and dedupe by id, and never report resultSizeEstimate as a count. A cheap backlog-residue probe each sweep (before:<anchor>, maxResults=5) surfaces pre-anchor unread loudly, so an anchored "no changes" can't mask a window the scan never saw.

personal-gmail is the only gmail-family plugin here, so it's the only file that changed.

1 files changed, 15 insertions, 0 deletions

diff --git a/claude-templates/.ai/workflows/triage-intake.personal-gmail.org b/claude-templates/.ai/workflows/triage-intake.personal-gmail.org
index a7af333..7d1ab4d 100644
--- a/claude-templates/.ai/workflows/triage-intake.personal-gmail.org
+++ b/claude-templates/.ai/workflows/triage-intake.personal-gmail.org
@@ -25,6 +25,21 @@ mcp__google-docs-personal__listMessages  q="is:unread in:inbox after:<anchor-epo
 
 ⚠ *Do NOT add =-category:promotions -category:social=.* That filter masked 67 promo+social messages across two runs (2026-05-04, 2026-05-06), both needing a follow-up sweep. Pull the full unfiltered set; the trash-leaning bias in Classify handles promotions and social directly.
 
+⚠ *The MCP caps at =maxResults=100= and exposes NO =pageToken= parameter.* The response carries a =nextPageToken=, but the tool can't consume it, so a pile over 100 is silently truncated — the tail below the cap never gets classified, and every later anchored sweep skips it (it predates the new anchor). This is exactly how a 300+ backlog accumulated invisibly by 2026-07-08. Two consequences:
+
+- *Never treat a 100-row result as complete.* When a scan returns exactly 100, walk the tail in *date slices*: re-query with =before:<oldest-full-day-seen>= (day resolution), repeat until a page returns fewer than 100, dedupe by message id across slices (the day-resolution boundary overlaps).
+- *Never report =resultSizeEstimate= as a count.* It's unreliable — observed stuck at "201" across three different queries whose real union exceeded 300.
+
+*** Backlog-residue check (every sweep — cheap, mandatory)
+
+The anchored scan is blind to anything unread from *before* the anchor. After it, run one probe for pre-anchor residue:
+
+#+begin_src text
+mcp__google-docs-personal__listMessages  q="is:unread in:inbox before:<anchor-YYYY/MM/DD>"  maxResults=5
+#+end_src
+
+If it returns any messages, surface one loud line in the sweep summary: "Backlog: unread predating the anchor exists (N+ shown; date-slice to inventory)" and offer a backlog sweep. Never fold the residue into a quiet sweep — an anchored "no changes" claim is only true for the window the scan saw. (Added 2026-07-08 after ~300 pre-anchor unread accumulated unseen; the probe returns actual messages, so it works where the estimate lies.)
+
 ** Classify
 
 Bias: *trash-leaning* — personal Gmail is high noise volume.