docs(solutions): compound the doc-reconciliation learnings; grow CONCEPTS.md

Captures the durable learnings from the 2026-07-25 whole-repo documentation
reconciliation as a knowledge-track learning, plus the vocabulary it introduced.

New learning — conventions/reconciling-drifted-docs-tense-tiering-and-a-supersession-ledger.md:

- Tier docs by TENSE, not only by content type. claude-md-content-tiering.md
  established "descriptions drift, rules don't" and tiered by content type; that
  axis could not say what to do with 41 completed plans, which are neither rules
  nor current descriptions. Present-tense docs are defects when stale; past-tense
  records are supposed to be stale and get annotated, never rewritten.
- Ledger AND inline notes, because each covers the other's failure: a ledger
  alone is a pointer you may not follow, inline notes alone give no changelog
  view. Prefer annotation patterns the repo already uses.
- Record what was NOT reversed, or a ledger of only reversals makes every old
  doc look suspect and settled decisions get re-litigated.
- Separate "docs are wrong" from "code is wrong" — route code-side findings to a
  recommendations doc so a docs diff stays reviewable.
- Verify against the artifact that decides behaviour: the Makefile for commands
  (including macro-generated targets a grep misses), the build script for
  outputs, imports for source-vs-output, branch history for whether a plan
  shipped. An audit that never withdraws a finding has not been checking itself
  — one finding here was withdrawn after reading package.json.
- Audit the state that actually runs: a fresh worktree checks out the submodule
  PIN, which lagged real HEAD and would have hidden a whole merged feature.

Three structural lessons in "Why This Matters":

- An index describing another document's role is a factual claim that can rot,
  and it is worse than the stale document itself — it defeats the reader's
  judgement before it engages. This was the tree's single most misleading line.
- Wrong beats absent again, now for commands: README's server runbook documented
  every remote-* target without the -test/-prod suffix guard-env requires.
  deploy-cycle.md had it right — the defect was a second copy drifting.
- Promoting a doc to "the authoritative list of X" creates a completeness
  obligation it did not have as prose, and nothing enforces it.
- A removal is not finished when the code is gone, but when every consumer and
  every description of it is gone — travel-memories left a compose service
  behind, hidden by a cached Docker image. Local state can mask a breakage
  indefinitely, so "it works here" is not evidence.

Overlap with conventions/claude-md-content-tiering.md scored MODERATE (2 of 5
dimensions: same root-cause thesis, overlapping files; different tiering axis
and different prevention), so a new doc was written rather than folding into it.
Flagged in the Related section as a consolidation candidate if a third
documentation learning appears.

CONCEPTS.md — new Documentation cluster (Historical record, Superseded decision,
Plan status) and one flagged ambiguity recording that a present-tense historical
record is not a claim about the current system. These three are now referenced by
CLAUDE.md and both doc READMEs, so they needed defining.

Discoverability check: no edit needed — CLAUDE.md's entry-point table already
surfaces docs/solutions/ with its frontmatter fields and CONCEPTS.md.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

CONCEPTS.md

@@ -48,6 +48,24 @@ A server's per-host configuration overlay. Once it exists, Grav's Admin writes *
 ### Remote-only plugin
 One of the project's three plugin-management categories, alongside GPM-managed (declared in the shared install list and restored by the standard install flow) and custom-in-repo (code tracked in the Content repo). A Remote-only plugin is installed explicitly on servers and restored by **no** standard flow — if its code goes missing it stays missing until someone reinstalls it deliberately, even while its configuration persists in the Env tree.
 
+## Documentation
+
+### Historical record
+A document that states what was decided or built at a past moment, not what is true now — plans, specs, milestone scopes, and session write-ups. Its going out of date is expected and is what makes it a record; it is corrected only by annotation, never by rewriting, because the value is the reasoning at the time.
+
+Distinguished from *current documentation*, which asserts how the system is today and is simply wrong when it drifts. A Historical record often reads in present tense, so the distinction is carried by an explicit marker rather than by tone.
+
+### Superseded decision
+Something the project planned or built and then deliberately reversed, recorded so the reversal is discoverable from the document that still describes the original. Each one names what was planned, what replaced it, when, and why.
+
+The record exists because a reversal is otherwise invisible: the old document keeps asserting the old thing, and the reasoning that killed it lives only in whoever remembers. A Superseded decision is the standing answer to "may I re-create this?" — usually no, and often the prohibition is also a hard rule.
+
+### Plan status
+The single recorded state of a plan, carried on the plan itself rather than in a separate tracker. **Deferred** and **Abandoned** are deliberately distinct: Deferred means still wanted but not now, Abandoned means decided against, kept so the decision is not re-litigated.
+
+A status that lags reality is worse than no status, because it is trusted — so it moves when the work lands, not later.
+
 ## Flagged ambiguities
 
 - "daily" / "entry" / "journal post" all refer to the same concept (a dated journal post). Canonical term: **Entry**. The section/folder is named "dailies" and the nav label is "Journal" — these name the *collection*, not a different entity.
+- A **Historical record** written in present tense is **not** a claim about the current system. Staleness there is correct; staleness in current documentation is a defect. When the two disagree, the code decides, and the gap is recorded as a **Superseded decision**.