Implement WP-0015-T02: extract policy/profile spec files

specs/policies/linear-longstop-v0.md extracted from
OpenQuestions-WorkingDefaults.md Q7's prose, with policy_id/title
frontmatter -- Q7 now records only the adoption decision, pointing at
this file for the formula itself.

Six specs/profiles/*.md files extracted from
CanonicalMonetizationProfiles.md's per-profile sections (#1-6), each
with extension_id/title frontmatter matching the ids already used in
real Phase Manifests. CanonicalMonetizationProfiles.md keeps the
cross-profile summary and non-goals sections, now pointing at the
extracted files instead of containing their content.

DevelopmentEffortCalculatorConcept.md gets calculator_id/revision/title
frontmatter for consistency, no move (already conformed as one file per
model). Checked for stale cross-references before editing -- nothing
in the repo links to the removed section anchors.

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

specs/policies/linear-longstop-v0.md

@@ -0,0 +1,43 @@
+---
+policy_id: trsl:policy:linear-longstop-v0@1.0
+title: Linear Longstop v0
+---
+
+# Linear Longstop v0
+
+Adopted 2026-07-29
+(`workplans/TREV-WP-0007-degeneration-policy-and-canonical-profiles.md`
+T02, maintainer-accepted): confirmed as the v1 norm for the first pilot
+cohort, not merely a Stage 0 pilot placeholder.
+
+## Definition
+
+- Remission accrues **only** by time toward a declared **Longstop Date**
+  (`specs/OpenQuestions-WorkingDefaults.md` Q8).
+- Between Phase activation `t0` and Longstop `tL`,
+
+  R(t) = T0 × clamp((t − t0)/(tL − t0), 0, 1)
+
+  with discrete ledger `remission-credit` entries computed on a published
+  schedule (e.g. daily or monthly UTC), **or** a single full remission at
+  longstop for minimal implementations.
+- Development Credit does not change the remission schedule in v0 (no
+  progress-sensitive boost/pause).
+
+## Status
+
+Not yet automated — see
+`workplans/TREV-WP-0013-remission-credit-automation.md`. Nothing in this
+codebase currently computes or writes these entries; this file is the
+formula those entries must be checkable against once that workplan lands.
+
+## Superseded / next iteration
+
+`specs/TargetDegenerationPolicyResearch.md` (T01) proposes a candidate
+`trsl:policy:progress-paused-longstop-v1` (a 90-day rolling "quiet
+period" pause on Remission Credit during active Development Credit
+periods), research complete but **not adopted**. Explicitly recommends
+*not* adopting a diversity-of-payers factor (no gaming-resistant signal
+exists yet). Named as the next iteration, to be revisited once real
+pilot Development Credit data exists — not required before pilot Phases
+proceed under v0.