docs(blog): the trust-layer essay on context rot and ADD

[TinDang97]

What

Adds blog/add-trust-layer-agentic.html — an editorial-scroll HTML essay for
engineering leaders evaluating ADD. Same convention as the existing
blog/add-25-vs-30-ledger.html: an artifact-style fragment, self-contained,
no CDN and no external fonts.

The piece runs a reason → resolve loop in eight acts:

Act	Beat
01	One call vs. an agentic loop — why one response was never enough
02	Context rot: the n² curve, plus Anthropic's four long-running-agent failure modes
03	The four context-engineering strategies — and the authority hole each leaves
04	ADD's answer: the task node, two memory tiers, the five living specs
05	The component digest — every piece of ADD, one line each
06	The transfer-money walkthrough, end to end
07	Capability matrix + the benchmark
08	Adoption

Where the claims come from

Everything factual is traceable to this repo or to Anthropic's published
material — nothing is invented to make the argument land:

• Failure modes are quoted from Anthropic's Effective harnesses for
  long-running agents. Mode 03 is paraphrased and says so on the page.
• Reveal panels under each failure mode are labelled
  illustrative reconstruction — they show the shape of the behaviour, and
  they are not presented as captured logs.
• The walkthrough is the canonical transfer example from
  GETTING-STARTED.md, including the verbatim refusal string
  (cannot freeze \transfer` — these (dimension, surface) pairs are unswept: who:S1`).
• Fig. 4 quotes real ## Deltas entries out of .add/specs/.
• Fig. 7 plots only the two measured points from README.md
  (coverage .92 → .75 in one continued conversation; ADD at 1.0 on fresh
  sessions). The unmeasured path is dashed and the table view says
  not plotted rather than filling in a curve.

Agentic turn counts and token deltas in act 01 are captioned
illustrative of the shape, not a measurement.

Craft notes

• Chart colours were run through the dataviz palette validator, not
  eyeballed, in both modes. Light #A8382F / #3E9E7C (deutan ΔE 13.4,
  normal-vision 27.1); dark #C45448 / #45AA88 (deutan ΔE 9.5, normal 25.2).
• Theme-aware across all three states — bare :root, the guarded
  prefers-color-scheme block, and [data-theme].
• Keyboard operable: the act-03 tablist takes arrow keys / Home / End; the
  act-02 reveals open on focus as well as hover.
• Honours prefers-reduced-motion; every chart has a table view; status is
  never encoded by colour alone.
• No innerHTML anywhere in the inline script.

Note for the reviewer

mkdocs.yml sets docs_dir: add-method/docs, so root blog/ is not built
into the published site. This lands the piece under version control and up
for review; it does not put it on pilotspace.github.io. Wiring it into the
site (a copy under add-method/docs/announcements/, plus nav) is a separate
call I deliberately left to you, since it changes what ships publicly.

Preview while reviewing: open the file directly in a browser, or read it as a
published artifact at
https://claude.ai/code/artifact/bdef431b-6d8e-4224-8456-27c0f132688f