P5a plan: PDF documents — seven Ornith tasks with acceptance tests first

docs/plans/p5a: 01 kind+fetch limits, 02 pdftext child + runner, 03 dcache PDF tables,
04 pdfpool, 05 pdfdoc render (map/pages/grep), 06 api, 07 digest citations, metrics, CLI,
skill, unit, README. Given tests compile against a panic-only skeleton and fail there for the
intended reasons; PDFs for tests are built by internal/pdftest (given), plus two qpdf-encrypted
fixtures.

Owner changes for the run: vendor go-pdfkit/extract v0.3.0 + reader v0.6.0 (pinned via
tools.go until task 02); AGENTS.md, tools/run-plan.sh (enforces a Co-Authored-By trailer for
the model), docs/implementer-log.md, `make gate`; gofmt (whitespace) on clean.go and guard;
TestUnsupportedType uses a zip now that PDFs are supported; requestDeadline 90→210 s and
writeTimeout 120→240 s for the PDF path's worst case.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

vendor/github.com/go-pdfkit/pdffont/greek.go

@@ -0,0 +1,69 @@
+package pdffont
+
+// greekAndMathRunes are the names a mathematical document gives its glyphs.
+// They are not in the Latin encodings, so a page of equations addressed by
+// name — which is what every TeX document is — could not be read back without
+// them: the words came out and the symbols did not.
+//
+// The names are Adobe's, from the Symbol font and the glyph list every
+// producer follows. They are checked against the documents themselves rather
+// than taken on trust: a font that carries both a name for a code and a
+// ToUnicode entry for it states the same fact twice, and the corpus has tens
+// of thousands of such pairs to compare against.
+var greekAndMathRunes = map[string]rune{
+	// The Greek alphabet, lower case and upper.
+	"alpha": 'α', "beta": 'β', "gamma": 'γ', "delta": 'δ', "epsilon": 'ε',
+	"zeta": 'ζ', "eta": 'η', "theta": 'θ', "iota": 'ι', "kappa": 'κ',
+	"lambda": 'λ', "mu1": 'μ', "nu": 'ν', "xi": 'ξ', "omicron": 'ο',
+	"pi": 'π', "rho": 'ρ', "sigma": 'σ', "sigma1": 'ς', "tau": 'τ',
+	"upsilon": 'υ', "phi": 'φ', "chi": 'χ', "psi": 'ψ', "omega": 'ω',
+	"theta1": 'ϑ', "phi1": 'ϕ', "epsilon1": 'ϵ', "rho1": 'ϱ', "omega1": 'ϖ',
+	"kappa1": 'ϰ', "pi1": 'ϖ',
+	// Adobe's list gives Delta and Omega the increment and ohm signs, which
+	// Unicode says are the same characters as the Greek letters written
+	// here — canonically equivalent, and these are the forms a person
+	// searching the text would type.
+	"Alpha": 'Α', "Beta": 'Β', "Gamma": 'Γ', "Delta": 'Δ', "Epsilon": 'Ε',
+	"Zeta": 'Ζ', "Eta": 'Η', "Theta": 'Θ', "Iota": 'Ι', "Kappa": 'Κ',
+	"Lambda": 'Λ', "Mu": 'Μ', "Nu": 'Ν', "Xi": 'Ξ', "Omicron": 'Ο',
+	"Pi": 'Π', "Rho": 'Ρ', "Sigma": 'Σ', "Tau": 'Τ', "Upsilon": 'Υ',
+	"Phi": 'Φ', "Chi": 'Χ', "Psi": 'Ψ', "Omega": 'Ω', "Upsilon1": 'ϒ',
+
+	// The signs an equation is built from.
+	"minus": '−', "plus": '+', "equal": '=', "asteriskmath": '∗',
+	"lessequal": '≤', "greaterequal": '≥', "notequal": '≠', "approxequal": '≈',
+	"equivalence": '≡', "similar": '∼', "congruent": '≅', "proportional": '∝',
+	"infinity": '∞', "partialdiff": '∂', "gradient": '∇', "integral": '∫',
+	"summation": '∑', "product": '∏', "radical": '√', "angle": '∠',
+	"perpendicular": '⊥', "therefore": '∴', "dotmath": '⋅', "bullet3": '∙',
+	"element": '∈', "notelement": '∉', "universal": '∀', "existential": '∃',
+	"emptyset": '∅', "intersection": '∩', "union": '∪',
+	"propersubset": '⊂', "propersuperset": '⊃',
+	"reflexsubset": '⊆', "reflexsuperset": '⊇', "notsubset": '⊄',
+	"logicaland": '∧', "logicalor": '∨', "logicalnot1": '¬',
+	"circleplus": '⊕', "circlemultiply": '⊗',
+	"prime": '′', "second": '″', "minute": '′',
+
+	// Arrows, and the brackets a display equation is built out of.
+	"arrowleft": '←', "arrowup": '↑', "arrowright": '→', "arrowdown": '↓',
+	"arrowboth": '↔', "arrowupdn": '↕',
+	"arrowdblleft": '⇐', "arrowdblup": '⇑', "arrowdblright": '⇒',
+	"arrowdbldown": '⇓', "arrowdblboth": '⇔',
+	"angleleft": '⟨', "angleright": '⟩',
+	"bracketlefttp": '⎡', "bracketleftbt": '⎣', "bracketleftex": '⎢',
+	"bracketrighttp": '⎤', "bracketrightbt": '⎦', "bracketrightex": '⎥',
+	"parenlefttp": '⎛', "parenleftbt": '⎝', "parenleftex": '⎜',
+	"parenrighttp": '⎞', "parenrightbt": '⎠', "parenrightex": '⎟',
+	"bracelefttp": '⎧', "braceleftmid": '⎨', "braceleftbt": '⎩',
+	"bracerighttp": '⎫', "bracerightmid": '⎬', "bracerightbt": '⎭',
+	"braceex": '⎪',
+
+	// The ligatures and marks a book is set with.
+	"ff": 'ff', "ffi": 'ffi', "ffl": 'ffl', "dotlessj": 'ȷ',
+	"circumflexbig": 'ˆ', "tildebig": '˜',
+	"suchthat": '∍', "carriagereturn": '↵', "aleph": 'ℵ',
+	"Ifraktur": 'ℑ', "Rfraktur": 'ℜ', "weierstrass": '℘',
+	"circlecopyrt": '©', "trademarksans": '™', "trademarkserif": '™',
+	"degree1": '°', "florin1": 'ƒ',
+	"lozenge": '◊', "spade": '♠', "club": '♣', "heart": '♥', "diamond": '♦',
+}