fix(preamble): learnings capture is unconditional at completion (#2402)

43 of 44 learnings entries came from explicit /learn — the completion-status
prose read 'if you discovered a durable project quirk... log it', which
models treated as optional. The step now ALWAYS runs: review the session for
durable learnings, log each one, and state 'No durable learnings this
session' explicitly when the review comes up empty — an empty result, never
a skipped step. Re-derived from PR #2612 under the generated-file screening
rule.

Fixes #2402.
Contributed by @Lockyer228

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

scripts/resolvers/preamble/generate-completion-status.ts

@@ -42,7 +42,13 @@ Escalate after 3 failed attempts, uncertain security-sensitive changes, or scope
 
 ## Operational Self-Improvement
 
-Before completing, if you discovered a durable project quirk or command fix that would save 5+ minutes next time, log it:
+Before completing, review the session for durable learnings and log each one —
+this step ALWAYS runs, it is not conditional on something feeling noteworthy
+(#2402: 43 of 44 learnings came from explicit /learn because "if you
+discovered" read as optional). A durable learning is a project quirk, command
+fix, pitfall, or pattern that would save 5+ minutes in a future session. If
+the review genuinely surfaces none, state "No durable learnings this session"
+in your completion summary — an explicit empty result, not a skipped step.
 
 \`\`\`bash
 ${ctx.paths.binDir}/gstack-learnings-log '{"skill":"SKILL_NAME","type":"operational","key":"SHORT_KEY","insight":"DESCRIPTION","confidence":N,"source":"observed"}'