docs: rename the working name "hotpath" to peltier.io in README and the book

The project ships as peltier.io; "hotpath" was the placeholder working name
(CLAUDE.md: "Rename freely; nothing depends on it"). Replaces the product
name in the README front page and every mdBook source chapter — book title,
nav header, and prose ("Peltier profiles…", "Peltier sells…") — plus the
theme CSS comment.

The metaphor is unchanged (a Peltier device is a thermoelectric cooler:
"spot cooling for hot paths"), and the literal noun phrase "hot paths"
stays. Two code identifiers are intentionally left as-is because they are
not prose: the `agent/hotpath_agent/` Python module path and the
`HOTPATH_ISOLATION` env var — renaming those is a code change, not a docs
one.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EcKPWQ3MQD4NdEHwar96u2

docs/book.toml

@@ -1,7 +1,7 @@
 [book]
-title = "hotpath"
+title = "peltier.io"
 description = "A profile-guided optimization agent that only ships wins it can prove."
-authors = ["hotpath"]
+authors = ["peltier.io"]
 language = "en"
 src = "src"
 

docs/src/SUMMARY.md

@@ -1,6 +1,6 @@
 # Summary
 
-[hotpath](./introduction.md)
+[peltier.io](./introduction.md)
 
 - [The thesis: trust is the product](./thesis.md)
 - [Architecture](./architecture.md)

docs/src/architecture.md

@@ -1,6 +1,6 @@
 # Architecture
 
-hotpath is split into a **trust layer** (Rust, the agent cannot write it)
+Peltier is split into a **trust layer** (Rust, the agent cannot write it)
 and an **untrusted proposer** (the agent). The split is structural, not
 advisory: the guarantees hold even if the proposer is adversarial.
 

docs/src/introduction.md

@@ -1,9 +1,9 @@
-# hotpath
+# peltier.io
 
 > Spot cooling for hot paths. A profile-guided optimization agent that
 > only ships wins it can prove.
 
-hotpath profiles real binaries and services, isolates hot paths, proposes
+Peltier profiles real binaries and services, isolates hot paths, proposes
 optimizations, and accepts a change **only** when two independent bars are
 cleared:
 
@@ -36,7 +36,7 @@ new gate.
 
 ## The differentiator
 
-Consultants sell surveys; compilers sell flags. hotpath sells **verified
+Consultants sell surveys; compilers sell flags. Peltier sells **verified
 deltas with the methodology attached** — a stopwatch on pinned hardware,
 a proof of equivalence, and an ROI figure whose confidence interval you
 can quote to a hostile reviewer. That is the entire product, and this site

docs/src/isolation.md

@@ -1,6 +1,6 @@
 # Isolation & anti-reward-hacking
 
-The guarantees only matter if the proposer cannot cheat. hotpath's defense
+The guarantees only matter if the proposer cannot cheat. Peltier's defense
 is **structural**: the agent is denied the capabilities it would need to
 manufacture a false win, at the OS level, not by prompt.
 

docs/src/measurement.md

@@ -46,7 +46,7 @@ shared runners — passed both bars before its numbers were trusted.
 Phase 4 measures latency under load, where the classic trap is
 **coordinated omission**: a closed-loop client that waits for a slow
 response simply sends fewer requests during the stall, so the stall never
-appears in the latency histogram. hotpath's load generator is **open-loop**
+appears in the latency histogram. Peltier's load generator is **open-loop**
 — requests are scheduled at a fixed rate and each latency is measured from
 its *intended* send time. When the server falls behind, the requests queued
 behind it each carry the full delay a real client would have seen. Nothing

docs/src/thesis.md

@@ -5,7 +5,7 @@ almost always some mix of a noisy benchmark, a workload that flatters the
 change, and a behavioral difference nobody checked. The number is real to
 the person who measured it and worthless to everyone downstream.
 
-hotpath is built on the opposite premise: **a performance claim is a
+Peltier is built on the opposite premise: **a performance claim is a
 liability until it is proven, and the proof ships with the number.**
 
 ## Three non-negotiables

docs/theme/custom.css

@@ -1,4 +1,4 @@
-/* hotpath docs — small refinements over the default mdBook theme. */
+/* peltier.io docs — small refinements over the default mdBook theme. */
 
 .content h1 {
     border-bottom: 2px solid var(--links);