Add API website metadata and branding

[SandroMaglione]

Summary

• add monochrome project branding across the API website, favicon, touch icons, manifest icons, and social card
• generate canonical, Open Graph, Twitter, theme-color, manifest, robots, and sitemap metadata through the existing static generator
• remove the visible internal v4 channel label and improve local preview MIME handling
• add regression coverage for production URLs and generated metadata

Changeset

• Added or updated for a library or package-metadata change
• Not required because this PR does not change src/ or package.json

Validation

• pnpm check
• Relevant example checks, when examples changed — not applicable
• Reviewed the automated type-performance report, when the public TypeScript API or inference changed — not applicable
• Reviewed the automated runtime-performance report, when runtime behavior changed — not applicable

Local visual QA was also completed at desktop and mobile widths.

[github-actions]

Type performance

Measured with TypeScript 6.0.3 and skipLibCheck=true.

Scenario	Base	PR	Difference
Effect only	55	55	0 (0.0%)
Import effect-machine	55	55	0 (0.0%)
Machine.defineStates (3 states)	2,965	2,965	0 (0.0%)
Machine.make (3 states, 2 events)	8,715	8,715	0 (0.0%)
machine.handle (3 states, 2 transitions)	23,492	23,492	0 (0.0%)
machine.handle (depth 8)	117,075	117,075	0 (0.0%)
machine.handle (depth 12)	129,713	129,713	0 (0.0%)
machine.handle (depth 16)	145,055	145,055	0 (0.0%)
machine.handle (depth 24)	183,851	183,851	0 (0.0%)
machine.handle (wide depth 16)	214,189	214,189	0 (0.0%)
machine.handle (parallel/history/choice)	132,667	132,667	0 (0.0%)
machine.handle (4 successive calls)	128,674	128,674	0 (0.0%)
machine exact input/output/error/services	110,584	110,584	0 (0.0%)
execution adapter readiness	127,854	127,854	0 (0.0%)

Marginal instantiations are measured against the matching setup without that API call:

Scenario	Base	PR	Difference
Import effect-machine	0	0	0
Machine.defineStates (3 states)	2,910	2,910	0 (0.0%)
Machine.make (3 states, 2 events)	5,742	5,742	0 (0.0%)
machine.handle (3 states, 2 transitions)	14,777	14,777	0 (0.0%)
machine.handle (depth 8)	109,601	109,601	0 (0.0%)
machine.handle (depth 12)	121,039	121,039	0 (0.0%)
machine.handle (depth 16)	135,181	135,181	0 (0.0%)
machine.handle (depth 24)	171,577	171,577	0 (0.0%)
machine.handle (wide depth 16)	202,224	202,224	0 (0.0%)
machine.handle (parallel/history/choice)	114,331	114,331	0 (0.0%)
machine.handle (4 successive calls)	113,703	113,703	0 (0.0%)
machine exact input/output/error/services	100,670	100,670	0 (0.0%)
execution adapter readiness	102,092	102,092	0 (0.0%)

Check times (informational)

Scenario	Base	PR
Effect only	0.03s	0.03s
Import effect-machine	0.03s	0.03s
Machine.defineStates (3 states)	0.10s	0.09s
Machine.make (3 states, 2 events)	0.15s	0.15s
machine.handle (3 states, 2 transitions)	0.23s	0.21s
machine.handle (depth 8)	0.51s	0.48s
machine.handle (depth 12)	0.54s	0.51s
machine.handle (depth 16)	0.57s	0.56s
machine.handle (depth 24)	0.65s	0.65s
machine.handle (wide depth 16)	0.71s	0.69s
machine.handle (parallel/history/choice)	0.57s	0.57s
machine.handle (4 successive calls)	0.56s	0.55s
machine exact input/output/error/services	0.49s	0.48s
execution adapter readiness	0.52s	0.54s

Type instantiations are the comparison metric. Check time varies with runner load and is informational only.

[github-actions]

Runtime performance

Median of 5 independent benchmark processes on AMD EPYC 7763 64-Core Processor with Node v24.18.0.

Pull request baseline

Scenario	Effect Machine	XState 5	XState 6 alpha
Plan counter transitions	130,653 transitions/s	135,119 transitions/s	13,063 transitions/s
Drain burst with terminal fence	506,311 increments/s	395,202 increments/s	193,089 increments/s
Drain burst with a change observer	465,863 increments/s	390,154 increments/s	193,634 increments/s
Lookup and send to one child	395,546 increments/s	388,964 increments/s	184,608 increments/s
Start and stop a machine	170,329 machines/s	187,970 machines/s	144,865 machines/s
Start and stop a parent with one child	33,393 families/s	69,358 families/s	41,261 families/s
Plan transitions through a compound state	119,993 transitions/s	—	—
Plan transitions through parallel regions	91,625 transitions/s	—	—
Drain burst through a compound state	504,001 events/s	344,261 events/s	189,534 events/s
Drain burst through two parallel regions	463,063 events/s	260,933 events/s	143,745 events/s
Drain a compound-state burst with a change observer	455,622 events/s	—	—

Effect runtime reference points

Scenario	Effect Machine	Effect runtime primitives
Start and stop a raw generic process	16,700 processes/s	—
Start and stop a raw compiled process	67,123 processes/s	—
Start and interrupt a suspended fiber	—	167,168 fibers/s
Start and stop a queue worker	—	116,877 workers/s
Start and stop an actor shell	—	105,507 actors/s
Start and stop two actor shells	—	65,885 families/s
Update an owner-only mutable snapshot	—	316,957,211 updates/s
Update a synchronized snapshot	—	1,528,753 updates/s
Create, resolve, and await a terminal latch	—	1,402,959 latches/s

Memory profile	Effect Machine	XState 5	XState 6 alpha	Effect runtime primitives
Idle machine	1.5 KiB	3.8 KiB	2.2 KiB	—
Raw generic managed process	12.7 KiB	—	—	—
Raw compiled process	2.8 KiB	—	—	—
Two independent idle machines	3.0 KiB	7.3 KiB	3.9 KiB	—
Idle parent with one child	4.8 KiB	5.5 KiB	4.0 KiB	—
Parent with observed child registry	9.0 KiB	—	—	—
Parent with observed invoked child snapshots	5.0 KiB	—	—	—
Suspended Effect fiber	—	—	—	0.6 KiB
Effect queue with waiting fiber	—	—	—	2.8 KiB
Effect mailbox actor shell	—	—	—	3.2 KiB
Two Effect actor shells	—	—	—	6.8 KiB

Effect Machine change from base

Metric	Base	Base variability	PR	PR variability	Difference
Plan counter transitions	130,936 transitions/s	3.3% MAD	130,653 transitions/s	4.4% MAD	-0.2%
Drain burst with terminal fence	514,654 increments/s	2.0% MAD	506,311 increments/s	2.4% MAD	-1.6%
Drain burst with a change observer	472,489 increments/s	1.1% MAD	465,863 increments/s	2.2% MAD	-1.4%
Lookup and send to one child	403,478 increments/s	0.9% MAD	395,546 increments/s	2.0% MAD	-2.0%
Start and stop a machine	170,648 machines/s	2.0% MAD	170,329 machines/s	2.3% MAD	-0.2%
Start and stop a parent with one child	32,995 families/s	0.4% MAD	33,393 families/s	3.2% MAD	+1.2%
Plan transitions through a compound state	119,676 transitions/s	0.4% MAD	119,993 transitions/s	0.3% MAD	+0.3%
Plan transitions through parallel regions	90,783 transitions/s	0.7% MAD	91,625 transitions/s	0.8% MAD	+0.9%
Drain burst through a compound state	498,583 events/s	0.5% MAD	504,001 events/s	0.8% MAD	+1.1%
Drain burst through two parallel regions	458,451 events/s	0.2% MAD	463,063 events/s	1.3% MAD	+1.0%
Drain a compound-state burst with a change observer	455,680 events/s	0.7% MAD	455,622 events/s	0.8% MAD	-0.0%
Idle machine heap per unit	1.5 KiB	0.1% MAD	1.5 KiB	0.1% MAD	+0.1%
Raw generic managed process heap per unit	12.7 KiB	0.0% MAD	12.7 KiB	0.0% MAD	-0.0%
Raw compiled process heap per unit	2.8 KiB	0.0% MAD	2.8 KiB	0.1% MAD	+0.1%
Two independent idle machines heap per unit	3.0 KiB	0.0% MAD	3.0 KiB	0.0% MAD	+0.0%
Idle parent with one child heap per unit	4.8 KiB	0.0% MAD	4.8 KiB	0.0% MAD	+0.0%
Parent with observed child registry heap per unit	9.0 KiB	0.0% MAD	9.0 KiB	0.0% MAD	+0.0%
Parent with observed invoked child snapshots heap per unit	5.0 KiB	0.2% MAD	5.0 KiB	0.2% MAD	+0.0%

Effect runtime reference change from base

Metric	Base	Base variability	PR	PR variability	Difference
Start and stop a raw generic process	16,900 processes/s	0.8% MAD	16,700 processes/s	1.0% MAD	-1.2%
Start and stop a raw compiled process	67,852 processes/s	0.5% MAD	67,123 processes/s	0.7% MAD	-1.1%
Start and interrupt a suspended fiber	166,639 fibers/s	0.7% MAD	167,168 fibers/s	0.5% MAD	+0.3%
Start and stop a queue worker	117,151 workers/s	0.7% MAD	116,877 workers/s	0.1% MAD	-0.2%
Start and stop an actor shell	106,986 actors/s	1.0% MAD	105,507 actors/s	0.5% MAD	-1.4%
Start and stop two actor shells	64,148 families/s	4.1% MAD	65,885 families/s	1.6% MAD	+2.7%
Update an owner-only mutable snapshot	316,856,781 updates/s	0.0% MAD	316,957,211 updates/s	0.0% MAD	+0.0%
Update a synchronized snapshot	1,549,638 updates/s	1.2% MAD	1,528,753 updates/s	2.8% MAD	-1.3%
Create, resolve, and await a terminal latch	1,416,178 latches/s	1.6% MAD	1,402,959 latches/s	0.6% MAD	-0.9%

Versions and interpretation

• Effect Machine: 0.4.0
• XState 5: 5.32.5
• XState 6 alpha: 6.0.0-alpha.31
• Effect runtime primitives: 4.0.0-beta.107

Higher throughput is better; lower heap is better. Variability is the median absolute deviation across independent processes, relative to their median. Runtime measurements on shared GitHub-hosted hardware remain informational, so small differences should be confirmed across multiple workflow runs.